Protracted Reproduction in Sunfish: the Temporal Dimension in Fish Recruitment Revisited

Understanding how life histories influence reproductive success under uncertain conditions is necessary to predict population dynamics. For many organisms, protracted reproduction may increase expected offspring recruitment in variable environments, requiring that temporal patterns of reproduction be considered when developing management or conservation strategies. We explored the interrelationships among birth date, production of embryos on nests, survival of larvae to the open-water stage, and survival of juveniles through the first fall and winter of life for bluegill and pumpkinseed sunfish (Lepomis macrochirus and L. gibbosus) in Lake Opinicon, Ontario, during May 1998 through May 1999. Age-0 sunfish were sampled with nesting surveys for embryos, surface tows for free-swimming larvae, and seining/trawling for juveniles. Age of juveniles (days post swim-up) was quantified using otoliths. The abundance of embryos on nests and the density of open-water larvae were unrelated across all dates and sites. Although 40% of larvae had appeared in the open water by 12 June, most juveniles sampled in the fall were produced after that time, suggesting that high mortality of early produced larvae occurred. Larval survival to the juvenile stage was generally unrelated to the abundance of edible zooplankton taxa during swim-up from nests. Larval survival was often highest at temperatures \u3e23.5°C. Fall length of age-0 sunfish increased with increasing age. Both age-specific length and mean lengths shifted positively between October 1998 and May 1999, suggesting that growth of all individuals and perhaps selective mortality of small juveniles occurred. Although early reproduction may increase sizes reached by fall and thereby improve overwinter survival, early hatched larvae are subject to variable environmental factors that may reduce survival. Late-hatched larvae may reach relatively smaller sizes by fall, but have higher survival probabilities during this life stage. Protracted reproduction appears to be a response to variable environmental factors influencing growth and survival across multiple life stages. As such, all reproducing adults, rather than those perceived to produce offspring during typically favorable times, must be protected from exploitation or other human-induced perturbations

Phase II Investigations at Prehistoric and Rock Art Sites, Justiceburg Reservoir, Garza and Kent Counties, Texas Volume I

Phase II cultural resources investigations at the proposed Justiceburg Reservoir in Garza and Kent counties, Texas, were conducted by Prewitt and Associates, Inc. in 19881989. This report documents the archeological work at 62 prehistoric and aboriginal rock art sites and the geoarcheological study conducted as part of the Phase II work. Investigations at 48 prehistoric sites, including open campsites, rockshelters, lithic procurement sites, faunal localities, and rock art sites, resulted in complete National Register assessments; 9 campsites, the 2 rockshelters, and 6 rock art sites are considered to be eligible for listing on the National Register of Historic Places. Less-intensive investigations at 14 prehistoric sites yielded insufficient data for full National Register assessments. The geoarcheological study resulted in the formulation of a model of the geomorphic history of the project area. Of considerable importance is the recognition of a period of catastrophic flushing of alluvial sediments Within the Double Mountain ~ork valley during the middle Holocene, followed by late Holocene sedimentation and stabilization. This supports the concept of a dry middle Holocene Altitherrnal period and helps explain the biased archeological record in the project area. The prehistoric site investigations indicate that most of the archeological remains present at Justiceburg Reservoir date to the late Archaic and Late Prehistoric periods, a phenomenon noted in similar settings elsewhere in the Lower Plains. Of the open campsites assessed as eligible for listing on the National Register, four are classified as late Archaic (4500-2000 B.P.), two are classified as Late Prehistoric I (2000-1000 8.P.), and three are classified as Late Prehistoric II (1000 B.P. to evidence of European contact). The two investigated rockshelters contain evidence of Late Prehistoric I and II occupations. Due to the paucity of regional archeological data and the lack of a well-defined cultural chronology, only two of these sites can be assigned tentatively to recognized cultural complexes. Site 4lGR291 yielded ceramics and arrow points indicating a Palo Duro Complex occupation, ca. A.D. 500, while ceramics and a distinctive hearth associated with the upper component at 41KTS3 suggest a Garza Complex occupation, ca. A.D. 1600-1700. No evidence of European contact was found at any of the habitation sites, but three of the rock art sites contain historic Plains Indian iconography. The investigations at the prehistoric sites resulted in the formulation of a late Holocene cuItural sequence for the project area. Analyses of the various classes of archeological evidence (e.g., artifacts, features, faunal remains) revealed broad cultural patterns that appear to reflect significant changes in subsistence strategies through time. It is suggested that these changes are related to late Holocene environmental conditions and corresponding shifts in the resource base. It is further suggested that bison were the most important resource controlling late Holocene human adaptations in the Texas Lower Plains

Phase II Investigations at Prehistoric and Rock Art Sites, Justiceburg Reservoir, Garza and Kent Counties, Texas Volume I

Phase II cultural resources investigations at the proposed Justiceburg Reservoir in Garza and Kent counties, Texas, were conducted by Prewitt and Associates, Inc. in 19881989. This report documents the archeological work at 62 prehistoric and aboriginal rock art sites and the geoarcheological study conducted as part of the Phase II work. Investigations at 48 prehistoric sites, including open campsites, rockshelters, lithic procurement sites, faunal localities, and rock art sites, resulted in complete National Register assessments; 9 campsites, the 2 rockshelters, and 6 rock art sites are considered to be eligible for listing on the National Register of Historic Places. Less-intensive investigations at 14 prehistoric sites yielded insufficient data for full National Register assessments. The geoarcheological study resulted in the formulation of a model of the geomorphic history of the project area. Of considerable importance is the recognition of a period of catastrophic flushing of alluvial sediments Within the Double Mountain ~ork valley during the middle Holocene, followed by late Holocene sedimentation and stabilization. This supports the concept of a dry middle Holocene Altitherrnal period and helps explain the biased archeological record in the project area. The prehistoric site investigations indicate that most of the archeological remains present at Justiceburg Reservoir date to the late Archaic and Late Prehistoric periods, a phenomenon noted in similar settings elsewhere in the Lower Plains. Of the open campsites assessed as eligible for listing on the National Register, four are classified as late Archaic (4500-2000 B.P.), two are classified as Late Prehistoric I (2000-1000 8.P.), and three are classified as Late Prehistoric II (1000 B.P. to evidence of European contact). The two investigated rockshelters contain evidence of Late Prehistoric I and II occupations. Due to the paucity of regional archeological data and the lack of a well-defined cultural chronology, only two of these sites can be assigned tentatively to recognized cultural complexes. Site 4lGR291 yielded ceramics and arrow points indicating a Palo Duro Complex occupation, ca. A.D. 500, while ceramics and a distinctive hearth associated with the upper component at 41KTS3 suggest a Garza Complex occupation, ca. A.D. 1600-1700. No evidence of European contact was found at any of the habitation sites, but three of the rock art sites contain historic Plains Indian iconography. The investigations at the prehistoric sites resulted in the formulation of a late Holocene cuItural sequence for the project area. Analyses of the various classes of archeological evidence (e.g., artifacts, features, faunal remains) revealed broad cultural patterns that appear to reflect significant changes in subsistence strategies through time. It is suggested that these changes are related to late Holocene environmental conditions and corresponding shifts in the resource base. It is further suggested that bison were the most important resource controlling late Holocene human adaptations in the Texas Lower Plains

Phase II Investigations at Prehistoric and Rock Art Sites, Justiceburg Reservoir, Garza and Kent Counties, Texas Volume I

Phase II cultural resources investigations at the proposed Justiceburg Reservoir in Garza and Kent counties, Texas, were conducted by Prewitt and Associates, Inc. in 19881989. This report documents the archeological work at 62 prehistoric and aboriginal rock art sites and the geoarcheological study conducted as part of the Phase II work. Investigations at 48 prehistoric sites, including open campsites, rockshelters, lithic procurement sites, faunal localities, and rock art sites, resulted in complete National Register assessments; 9 campsites, the 2 rockshelters, and 6 rock art sites are considered to be eligible for listing on the National Register of Historic Places. Less-intensive investigations at 14 prehistoric sites yielded insufficient data for full National Register assessments. The geoarcheological study resulted in the formulation of a model of the geomorphic history of the project area. Of considerable importance is the recognition of a period of catastrophic flushing of alluvial sediments Within the Double Mountain ~ork valley during the middle Holocene, followed by late Holocene sedimentation and stabilization. This supports the concept of a dry middle Holocene Altitherrnal period and helps explain the biased archeological record in the project area. The prehistoric site investigations indicate that most of the archeological remains present at Justiceburg Reservoir date to the late Archaic and Late Prehistoric periods, a phenomenon noted in similar settings elsewhere in the Lower Plains. Of the open campsites assessed as eligible for listing on the National Register, four are classified as late Archaic (4500-2000 B.P.), two are classified as Late Prehistoric I (2000-1000 8.P.), and three are classified as Late Prehistoric II (1000 B.P. to evidence of European contact). The two investigated rockshelters contain evidence of Late Prehistoric I and II occupations. Due to the paucity of regional archeological data and the lack of a well-defined cultural chronology, only two of these sites can be assigned tentatively to recognized cultural complexes. Site 4lGR291 yielded ceramics and arrow points indicating a Palo Duro Complex occupation, ca. A.D. 500, while ceramics and a distinctive hearth associated with the upper component at 41KTS3 suggest a Garza Complex occupation, ca. A.D. 1600-1700. No evidence of European contact was found at any of the habitation sites, but three of the rock art sites contain historic Plains Indian iconography. The investigations at the prehistoric sites resulted in the formulation of a late Holocene cuItural sequence for the project area. Analyses of the various classes of archeological evidence (e.g., artifacts, features, faunal remains) revealed broad cultural patterns that appear to reflect significant changes in subsistence strategies through time. It is suggested that these changes are related to late Holocene environmental conditions and corresponding shifts in the resource base. It is further suggested that bison were the most important resource controlling late Holocene human adaptations in the Texas Lower Plains

Phase II Investigations at Prehistoric and Rock Art Sites, Justiceburg Reservoir, Garza and Kent Counties, Texas Volume I

Phase II cultural resources investigations at the proposed Justiceburg Reservoir in Garza and Kent counties, Texas, were conducted by Prewitt and Associates, Inc. in 19881989. This report documents the archeological work at 62 prehistoric and aboriginal rock art sites and the geoarcheological study conducted as part of the Phase II work. Investigations at 48 prehistoric sites, including open campsites, rockshelters, lithic procurement sites, faunal localities, and rock art sites, resulted in complete National Register assessments; 9 campsites, the 2 rockshelters, and 6 rock art sites are considered to be eligible for listing on the National Register of Historic Places. Less-intensive investigations at 14 prehistoric sites yielded insufficient data for full National Register assessments. The geoarcheological study resulted in the formulation of a model of the geomorphic history of the project area. Of considerable importance is the recognition of a period of catastrophic flushing of alluvial sediments Within the Double Mountain ~ork valley during the middle Holocene, followed by late Holocene sedimentation and stabilization. This supports the concept of a dry middle Holocene Altitherrnal period and helps explain the biased archeological record in the project area. The prehistoric site investigations indicate that most of the archeological remains present at Justiceburg Reservoir date to the late Archaic and Late Prehistoric periods, a phenomenon noted in similar settings elsewhere in the Lower Plains. Of the open campsites assessed as eligible for listing on the National Register, four are classified as late Archaic (4500-2000 B.P.), two are classified as Late Prehistoric I (2000-1000 8.P.), and three are classified as Late Prehistoric II (1000 B.P. to evidence of European contact). The two investigated rockshelters contain evidence of Late Prehistoric I and II occupations. Due to the paucity of regional archeological data and the lack of a well-defined cultural chronology, only two of these sites can be assigned tentatively to recognized cultural complexes. Site 4lGR291 yielded ceramics and arrow points indicating a Palo Duro Complex occupation, ca. A.D. 500, while ceramics and a distinctive hearth associated with the upper component at 41KTS3 suggest a Garza Complex occupation, ca. A.D. 1600-1700. No evidence of European contact was found at any of the habitation sites, but three of the rock art sites contain historic Plains Indian iconography. The investigations at the prehistoric sites resulted in the formulation of a late Holocene cuItural sequence for the project area. Analyses of the various classes of archeological evidence (e.g., artifacts, features, faunal remains) revealed broad cultural patterns that appear to reflect significant changes in subsistence strategies through time. It is suggested that these changes are related to late Holocene environmental conditions and corresponding shifts in the resource base. It is further suggested that bison were the most important resource controlling late Holocene human adaptations in the Texas Lower Plains

Phase II Investigations at Prehistoric and Rock Art Sites, Justiceburg Reservoir, Garza and Kent Counties, Texas Volume I

Phase II cultural resources investigations at the proposed Justiceburg Reservoir in Garza and Kent counties, Texas, were conducted by Prewitt and Associates, Inc. in 19881989. This report documents the archeological work at 62 prehistoric and aboriginal rock art sites and the geoarcheological study conducted as part of the Phase II work. Investigations at 48 prehistoric sites, including open campsites, rockshelters, lithic procurement sites, faunal localities, and rock art sites, resulted in complete National Register assessments; 9 campsites, the 2 rockshelters, and 6 rock art sites are considered to be eligible for listing on the National Register of Historic Places. Less-intensive investigations at 14 prehistoric sites yielded insufficient data for full National Register assessments. The geoarcheological study resulted in the formulation of a model of the geomorphic history of the project area. Of considerable importance is the recognition of a period of catastrophic flushing of alluvial sediments Within the Double Mountain ~ork valley during the middle Holocene, followed by late Holocene sedimentation and stabilization. This supports the concept of a dry middle Holocene Altitherrnal period and helps explain the biased archeological record in the project area. The prehistoric site investigations indicate that most of the archeological remains present at Justiceburg Reservoir date to the late Archaic and Late Prehistoric periods, a phenomenon noted in similar settings elsewhere in the Lower Plains. Of the open campsites assessed as eligible for listing on the National Register, four are classified as late Archaic (4500-2000 B.P.), two are classified as Late Prehistoric I (2000-1000 8.P.), and three are classified as Late Prehistoric II (1000 B.P. to evidence of European contact). The two investigated rockshelters contain evidence of Late Prehistoric I and II occupations. Due to the paucity of regional archeological data and the lack of a well-defined cultural chronology, only two of these sites can be assigned tentatively to recognized cultural complexes. Site 4lGR291 yielded ceramics and arrow points indicating a Palo Duro Complex occupation, ca. A.D. 500, while ceramics and a distinctive hearth associated with the upper component at 41KTS3 suggest a Garza Complex occupation, ca. A.D. 1600-1700. No evidence of European contact was found at any of the habitation sites, but three of the rock art sites contain historic Plains Indian iconography. The investigations at the prehistoric sites resulted in the formulation of a late Holocene cuItural sequence for the project area. Analyses of the various classes of archeological evidence (e.g., artifacts, features, faunal remains) revealed broad cultural patterns that appear to reflect significant changes in subsistence strategies through time. It is suggested that these changes are related to late Holocene environmental conditions and corresponding shifts in the resource base. It is further suggested that bison were the most important resource controlling late Holocene human adaptations in the Texas Lower Plains

Phase II Investigations at Prehistoric and Rock Art Sites, Justiceburg Reservoir, Garza and Kent Counties, Texas Volume I

Phase II cultural resources investigations at the proposed Justiceburg Reservoir in Garza and Kent counties, Texas, were conducted by Prewitt and Associates, Inc. in 19881989. This report documents the archeological work at 62 prehistoric and aboriginal rock art sites and the geoarcheological study conducted as part of the Phase II work. Investigations at 48 prehistoric sites, including open campsites, rockshelters, lithic procurement sites, faunal localities, and rock art sites, resulted in complete National Register assessments; 9 campsites, the 2 rockshelters, and 6 rock art sites are considered to be eligible for listing on the National Register of Historic Places. Less-intensive investigations at 14 prehistoric sites yielded insufficient data for full National Register assessments. The geoarcheological study resulted in the formulation of a model of the geomorphic history of the project area. Of considerable importance is the recognition of a period of catastrophic flushing of alluvial sediments Within the Double Mountain ~ork valley during the middle Holocene, followed by late Holocene sedimentation and stabilization. This supports the concept of a dry middle Holocene Altitherrnal period and helps explain the biased archeological record in the project area. The prehistoric site investigations indicate that most of the archeological remains present at Justiceburg Reservoir date to the late Archaic and Late Prehistoric periods, a phenomenon noted in similar settings elsewhere in the Lower Plains. Of the open campsites assessed as eligible for listing on the National Register, four are classified as late Archaic (4500-2000 B.P.), two are classified as Late Prehistoric I (2000-1000 8.P.), and three are classified as Late Prehistoric II (1000 B.P. to evidence of European contact). The two investigated rockshelters contain evidence of Late Prehistoric I and II occupations. Due to the paucity of regional archeological data and the lack of a well-defined cultural chronology, only two of these sites can be assigned tentatively to recognized cultural complexes. Site 4lGR291 yielded ceramics and arrow points indicating a Palo Duro Complex occupation, ca. A.D. 500, while ceramics and a distinctive hearth associated with the upper component at 41KTS3 suggest a Garza Complex occupation, ca. A.D. 1600-1700. No evidence of European contact was found at any of the habitation sites, but three of the rock art sites contain historic Plains Indian iconography. The investigations at the prehistoric sites resulted in the formulation of a late Holocene cuItural sequence for the project area. Analyses of the various classes of archeological evidence (e.g., artifacts, features, faunal remains) revealed broad cultural patterns that appear to reflect significant changes in subsistence strategies through time. It is suggested that these changes are related to late Holocene environmental conditions and corresponding shifts in the resource base. It is further suggested that bison were the most important resource controlling late Holocene human adaptations in the Texas Lower Plains

Phase II Investigations at Prehistoric and Rock Art Sites, Justiceburg Reservoir, Garza and Kent Counties, Texas Volume I

Phase II cultural resources investigations at the proposed Justiceburg Reservoir in Garza and Kent counties, Texas, were conducted by Prewitt and Associates, Inc. in 19881989. This report documents the archeological work at 62 prehistoric and aboriginal rock art sites and the geoarcheological study conducted as part of the Phase II work. Investigations at 48 prehistoric sites, including open campsites, rockshelters, lithic procurement sites, faunal localities, and rock art sites, resulted in complete National Register assessments; 9 campsites, the 2 rockshelters, and 6 rock art sites are considered to be eligible for listing on the National Register of Historic Places. Less-intensive investigations at 14 prehistoric sites yielded insufficient data for full National Register assessments. The geoarcheological study resulted in the formulation of a model of the geomorphic history of the project area. Of considerable importance is the recognition of a period of catastrophic flushing of alluvial sediments Within the Double Mountain ~ork valley during the middle Holocene, followed by late Holocene sedimentation and stabilization. This supports the concept of a dry middle Holocene Altitherrnal period and helps explain the biased archeological record in the project area. The prehistoric site investigations indicate that most of the archeological remains present at Justiceburg Reservoir date to the late Archaic and Late Prehistoric periods, a phenomenon noted in similar settings elsewhere in the Lower Plains. Of the open campsites assessed as eligible for listing on the National Register, four are classified as late Archaic (4500-2000 B.P.), two are classified as Late Prehistoric I (2000-1000 8.P.), and three are classified as Late Prehistoric II (1000 B.P. to evidence of European contact). The two investigated rockshelters contain evidence of Late Prehistoric I and II occupations. Due to the paucity of regional archeological data and the lack of a well-defined cultural chronology, only two of these sites can be assigned tentatively to recognized cultural complexes. Site 4lGR291 yielded ceramics and arrow points indicating a Palo Duro Complex occupation, ca. A.D. 500, while ceramics and a distinctive hearth associated with the upper component at 41KTS3 suggest a Garza Complex occupation, ca. A.D. 1600-1700. No evidence of European contact was found at any of the habitation sites, but three of the rock art sites contain historic Plains Indian iconography. The investigations at the prehistoric sites resulted in the formulation of a late Holocene cuItural sequence for the project area. Analyses of the various classes of archeological evidence (e.g., artifacts, features, faunal remains) revealed broad cultural patterns that appear to reflect significant changes in subsistence strategies through time. It is suggested that these changes are related to late Holocene environmental conditions and corresponding shifts in the resource base. It is further suggested that bison were the most important resource controlling late Holocene human adaptations in the Texas Lower Plains

Phase II Investigations at Prehistoric and Rock Art Sites, Justiceburg Reservoir, Garza and Kent Counties, Texas Volume I

Phase II cultural resources investigations at the proposed Justiceburg Reservoir in Garza and Kent counties, Texas, were conducted by Prewitt and Associates, Inc. in 19881989. This report documents the archeological work at 62 prehistoric and aboriginal rock art sites and the geoarcheological study conducted as part of the Phase II work. Investigations at 48 prehistoric sites, including open campsites, rockshelters, lithic procurement sites, faunal localities, and rock art sites, resulted in complete National Register assessments; 9 campsites, the 2 rockshelters, and 6 rock art sites are considered to be eligible for listing on the National Register of Historic Places. Less-intensive investigations at 14 prehistoric sites yielded insufficient data for full National Register assessments. The geoarcheological study resulted in the formulation of a model of the geomorphic history of the project area. Of considerable importance is the recognition of a period of catastrophic flushing of alluvial sediments Within the Double Mountain ~ork valley during the middle Holocene, followed by late Holocene sedimentation and stabilization. This supports the concept of a dry middle Holocene Altitherrnal period and helps explain the biased archeological record in the project area. The prehistoric site investigations indicate that most of the archeological remains present at Justiceburg Reservoir date to the late Archaic and Late Prehistoric periods, a phenomenon noted in similar settings elsewhere in the Lower Plains. Of the open campsites assessed as eligible for listing on the National Register, four are classified as late Archaic (4500-2000 B.P.), two are classified as Late Prehistoric I (2000-1000 8.P.), and three are classified as Late Prehistoric II (1000 B.P. to evidence of European contact). The two investigated rockshelters contain evidence of Late Prehistoric I and II occupations. Due to the paucity of regional archeological data and the lack of a well-defined cultural chronology, only two of these sites can be assigned tentatively to recognized cultural complexes. Site 4lGR291 yielded ceramics and arrow points indicating a Palo Duro Complex occupation, ca. A.D. 500, while ceramics and a distinctive hearth associated with the upper component at 41KTS3 suggest a Garza Complex occupation, ca. A.D. 1600-1700. No evidence of European contact was found at any of the habitation sites, but three of the rock art sites contain historic Plains Indian iconography. The investigations at the prehistoric sites resulted in the formulation of a late Holocene cuItural sequence for the project area. Analyses of the various classes of archeological evidence (e.g., artifacts, features, faunal remains) revealed broad cultural patterns that appear to reflect significant changes in subsistence strategies through time. It is suggested that these changes are related to late Holocene environmental conditions and corresponding shifts in the resource base. It is further suggested that bison were the most important resource controlling late Holocene human adaptations in the Texas Lower Plains

Phase II Investigations at Prehistoric and Rock Art Sites, Justiceburg Reservoir, Garza and Kent Counties, Texas Volume I

Phase II cultural resources investigations at the proposed Justiceburg Reservoir in Garza and Kent counties, Texas, were conducted by Prewitt and Associates, Inc. in 19881989. This report documents the archeological work at 62 prehistoric and aboriginal rock art sites and the geoarcheological study conducted as part of the Phase II work. Investigations at 48 prehistoric sites, including open campsites, rockshelters, lithic procurement sites, faunal localities, and rock art sites, resulted in complete National Register assessments; 9 campsites, the 2 rockshelters, and 6 rock art sites are considered to be eligible for listing on the National Register of Historic Places. Less-intensive investigations at 14 prehistoric sites yielded insufficient data for full National Register assessments. The geoarcheological study resulted in the formulation of a model of the geomorphic history of the project area. Of considerable importance is the recognition of a period of catastrophic flushing of alluvial sediments Within the Double Mountain ~ork valley during the middle Holocene, followed by late Holocene sedimentation and stabilization. This supports the concept of a dry middle Holocene Altitherrnal period and helps explain the biased archeological record in the project area. The prehistoric site investigations indicate that most of the archeological remains present at Justiceburg Reservoir date to the late Archaic and Late Prehistoric periods, a phenomenon noted in similar settings elsewhere in the Lower Plains. Of the open campsites assessed as eligible for listing on the National Register, four are classified as late Archaic (4500-2000 B.P.), two are classified as Late Prehistoric I (2000-1000 8.P.), and three are classified as Late Prehistoric II (1000 B.P. to evidence of European contact). The two investigated rockshelters contain evidence of Late Prehistoric I and II occupations. Due to the paucity of regional archeological data and the lack of a well-defined cultural chronology, only two of these sites can be assigned tentatively to recognized cultural complexes. Site 4lGR291 yielded ceramics and arrow points indicating a Palo Duro Complex occupation, ca. A.D. 500, while ceramics and a distinctive hearth associated with the upper component at 41KTS3 suggest a Garza Complex occupation, ca. A.D. 1600-1700. No evidence of European contact was found at any of the habitation sites, but three of the rock art sites contain historic Plains Indian iconography. The investigations at the prehistoric sites resulted in the formulation of a late Holocene cuItural sequence for the project area. Analyses of the various classes of archeological evidence (e.g., artifacts, features, faunal remains) revealed broad cultural patterns that appear to reflect significant changes in subsistence strategies through time. It is suggested that these changes are related to late Holocene environmental conditions and corresponding shifts in the resource base. It is further suggested that bison were the most important resource controlling late Holocene human adaptations in the Texas Lower Plains