Unnamed Thermal Spring
This spring on BLM land in Owyhee County flows at 122°F (50°C per USGS measurements) with remarkably alkaline chemistry: pH 9.5 and extraordinarily low calcium (2.0 mg/L) and magnesium (0.08 mg/L). The water contains 180 mg/L sodium, 65 mg/L sulfate, and 80 mg/L chloride, signature of deep geothermal circulation through volcanic rock.
Situated at 3,120 feet elevation within the Vale Malheur Field Office jurisdiction, the spring lies in rugged canyon country where the Snake River basalts dominate geology. The site sits 1,543 meters from the nearest road, requiring a half-mile walk through desert scrubland of sagebrush, rabbitbrush, and occasional juniper. The arid climate delivers just 10.3 inches of annual precipitation and 17 inches of snow, with average air temperatures of 54.9°F. Surrounding canyons cut through layered volcanic flows, creating dramatic topographic relief.
This unnamed spring appears in the 1980 NOAA thermal springs inventory but carries no recorded development history or Indigenous name. The remote location along the Oregon-Idaho border in sparsely settled Owyhee County likely kept it outside historic travel corridors, though Shoshone and Paiute groups traversed the broader region.
Access requires navigating BLM roads and a moderate walk; verify current road conditions before departure. The highly alkaline water may irritate skin during prolonged exposure. Spring through fall offer optimal visiting conditions; summer temperatures exceed 95°F. Carry detailed maps as cellular coverage is nonexistent. The extreme chemistry makes this site more valuable for study than recreation.
The water at This spring is alkaline (pH 8.9).