This report presents results of analyses made at the Laramie Energy Research Center of three cores from an area at the northern end of Seep Ridge in the P.R. Spring tar sand deposit in northeastern Utah. Up to five tar sand zones have been identified in the north Seep Ridge area. These zones occur between the depths of 9 and 390 feet and have a thickness ranging from 27 to 97 feet. The total tar sand section has good porosity, averaging 20.9 pct of bulk volume; fair permeability, 58.9 md before oil extraction and 384 md after oil extraction; and low oil saturation, 38.6 pct of pore volume. The oil has an average gravity of 10.1 degrees API, an average sulfur content of 0.40 weight pct, and an average nitrogen content of 1.30 weight pct.