ABSTRACT
The Green River Basin of Wyoming, Colorado, and Utah is a part of the Upper Colorado River Basin and has many scenic and mineral resources. High concentra tions of salts, selenium, and other trace elements are associated with the sedimen tary formations of the basin, and mobilization of these salts and elements has been and is a problem for irrigation in the region. The Upper Colorado River Basin is regarded as the greatest contributor of salinity to the Colorado River (U.S. Environmental Protection Agency, 1971). As early as 1935, drainage from irrigated soils high in selenium was identified as a source of elevated selenium concentrations in the Colorado River and its tributaries by Williams and Byers (1935).
