The James Lister well (Sec. 27, T24N, R43E), a nonflowing 5-m-deep artesian well, has a reported temperature of 38.9°C (Waring, 1919). A well (SE¼ SE¼ Sec. 35, T24N, R43E) at the Steiner Ranch, about 2 km to the southeast, is also reported to be hot (Basinski, 1978, p. 60). Hot water (about 60°C) was encountered in uranium exploration drill holes about 2 km west of Steiner Ranch (C E½ Sec. 5 and C W½ Sec. 4, T23N, R43E) at a depth of about 107 m. (Basinski, 1978, p. 60). The maximum temperature reported from AMAX and Phillips Petroleum Co. gradient drill holes was 68.3ºC at 137 m (GeothermEx, 2004, Fig. SHO00-1). Anomalous temperature gradients were found in drill holes along a northeast-trending zone (4.8 km long by 1.6 km wide) that is coincident with a probable fault that bounds the southeast side of a small graben. Mercury soil gas and radiometric surveys have been applied in the area (Henkle and others, 2005a, b).
Sierra Geothermal Power Corp. drilled a 1,198-m exploration well (No. 56-4) in March 2007. Temperatures of at least 124°C were recorded, and a positive temperature gradient was present throughout the well (see (www.sierrageopower.com/)for more information). Partial funding of $580,000 for the well was provided by the US Department of Energy's GRED III program.