Surface soil and topsoil samples from experimental test sites in western North Dakota were aseptically collected during August 1975 and from May through September during 1976-77. Selected samples were cultured in a defined inorganic medium and after 6 weeks the algae were identified. Chlorophyll a content of the soil and spoil was used as a measure of the algal abundance. Soil physical- chemical properties, species variety, and abundance were statistically analyzed. All test sites revealed distinct soil algal communities and demonstrated a successional trend as evidenced by significant increases in species variety and biomass over time. Some soil factors (ca, cu, and p) affected species variety and abundance at more than one site. Others were important at specific sites (si and al at one site; mn, na, and zn at another site; and b, cd, and mg at another site). Topsoiled areas had higher species varieties and abundances when compared with control areas, as did plots treated with amendments such as leonardite and fertilizer.