Dunn Spring
Dunn Spring flows at 70°F within the Malheur National Wildlife Refuge at 4,101 feet elevation, emerging 19.9°F above the ambient temperature in a restricted-access area managed by the US Fish and Wildlife Service. The spring requires a 1,867-meter hike from the nearest road, making it one of the more remote thermal features in Harney County's refuge system.
The spring emerges in the driest section of the Malheur refuge, where annual precipitation totals just 11.6 inches with 21.7 inches of snow—among the lowest values for any Oregon thermal spring. The terrain features alkali flats, sparse greasewood, and seasonal wetlands at 4,101 feet elevation, surrounded by the stark beauty of Oregon's high desert. The 1.2-mile approach crosses sagebrush uplands and playa margins where pronghorn antelope and migratory waterfowl utilize the scattered water sources in an otherwise harsh environment.
The spring takes its name from an early rancher or homesteader in the Harney Basin, though specific historical records about the Dunn family connection remain sparse in published sources. The Malheur region saw waves of homesteading from the 1870s through early 1900s, with water sources like this spring crucial to survival and livestock operations. Federal acquisition created the refuge in 1908, incorporating existing place names into the protected landscape where springs continue to support wildlife rather than cattle.
Access requires advance coordination with refuge staff and is typically limited to research or wildlife management purposes given the restricted status. The 1.2-mile hike demands desert navigation skills and adequate water supplies, as the warm spring itself is not suitable for drinking. Best visited during moderate seasons (April-May, September-October) when temperatures avoid summer extremes above 95°F and winter lows near 0°F. Elevation and sun exposure require sun protection year-round.