Wilson Hot Spring (SE¼ SW¼ Sec. 34, T11N, R25E; Yerington 15-minute topographic map) was reportedly dry in 1969 (Alvin McLane, personal commun., 1973), with steaming ground at the site (Williams, 1996, p. 6). A temperature of 94ºC was measured at a fumarole in 1983 (Robert Mariner, unpubl. data). Between 1976 and 1978 Chevron drilled 34 exploratory boreholes ranging in depth from 30.5 to 609.8 m and found temperatures ranging from 16.3 to 90.9 ºC (Sass and others, 1999). No information is available on the other Mason Valley hot spring 9.6 km to the north (NW¼ NE¼ SW¼ Sec. 34, T12N, R25E, about 0.5 km west of the West Walker River).