A site characterization study was conducted at an old oil production area where highest activity occurred during the 1930's. Two site locations referred to as OSPER are along the shoreline of Skiatook Lake northwest of Tulsa, Oklahoma. Crude oil and brine water releases have impacted soils, surface and ground water, and the Oak cross-timber ecosystem. Local effects include soil salinization with destruction of plant cover and soil texture, and resultant deep erosion. Stress on affected vegetation is prevalent, but some grass revegetation has occurred. Surface soil samples and vertical profile cores to four feet have been collected and analyzed for salinity, organic matter, petroleum hydrocarbons, texture, nitrates, and dehydrogenase activity. Native grass re-establishment was inversely related to soil salinity and extent of erosion. As expected oil wastes increased the soil organic matter, greatly over surface controls near 0.3%.. Natural soil nitrates were at a low level near 0.2 ppm, but sufficient to support native grasses.