Richards and Blackwell (2002) suggest that an area near Lockwood is of potential interest for geothermal exploration, based on the temperature gradient of about 210ºC/km indicated by a maximum temperature of 33.3ºC in a 32 m-deep well (SMU; Sass and others, 1999). Granite Construction’s gravel pit, on the north side of Interstate 80, has two wells on the property. The eastern well is ~26ºC and was sampled in April 2006. The western well is reported to have temperatures in excess of 30ºC, however, Granite Construction did not allow access to it. Location: 39.51ºN, 119.65ºW.