Continued exploration in the Basin and Range of Nevada has resulted in a number of small field discoveries that confirm widespread oil generation and suggest potential in local prospect settings. One such setting, the Lone Tree prospect area, lies approximately 6.5 mi (10.4 km) southwest of Grant Canyon field in Railroad Valley. Discovered in 1983, this field had produced nearly 20 million bbl of oil by June 1996, mostly from two wells. Oil is entrapped in a slide block of fractured Paleozoic strata juxtaposed against Mississippian source rocks along a detachment fault of probable early Tertiary age. Subsequent exploration has focused on attempts to identify such blocks elsewhere in east-central Nevada, particularly in Railroad and Pine valleys. Well, gravity, and two-dimensional seismic data suggested the existence of such a block in the Lone Tree area. These data were used as a basis for a three-dimensional seismic survey. Information from this survey identified a prospect at the structural culmination of the interpreted block. The resulting well, the 13-14 Timber Mountain, was commercially unsuccessful but yielded important new data, suggesting a need to revise existing stratigraphy and structural history. In addition, a second prospect, located farther updip, was indicated.