Biweekly diatom collections and chemical analyses were made in the autumn of 1970 from sites on Brewer\u27s Creek, a small central Iowa stream, and the Boone River. Eight diatom collection sites and five chemical analysis sites were used. Diatom population data and chemical data both indicate that this is a high alkaline, eutrophic stream. The creek water has a high conductivity which may, in part, explain why diatoms considered to be mesohalobous are present in the collections