The basin was formed approximately 32,000 years ago when
lava flows formed the
Malheur Gap, separating the
watershed of the basin from the
Malheur River, a tributary of the Snake River.
Archaeological evidence indicates the basin was inhabited as early as 10,000 years ago. Pollen records indicate that the climate, especially the level of rain and snowfall, has varied greatly since the end of the
Pleistocene. Evidence of prehistoric fishing techniques is found at several sites. Evidence suggests that there existed in the basin several species—in particular, the
chiselmouth,
coarse-scale suckers, and
northern squawfish—that are currently found only in the
Columbia River basin, indicating that at some point the Harney Basin may have been connected to the Columbia. During wetter years, the lake level of Malheur Lake was raised to a depth of , allowing the lakes to drain over the Malheur Gap. In modern times, however, the lake level does not rise above in the wettest years. In the 19th century, the basin was inhabited by the
Northern Paiute tribe. It was explored and extensively trapped by
trappers of the
Hudson's Bay Company in the 1820s. The basin lay far off the route of the
Oregon Trail, but in 1845 experienced mountain man
Stephen Meek led an ill-fated party across the basin via
Stinkingwater Pass, seeking a shortcut to
The Dalles along what has become known as the
Meek Cutoff. A total of 23 people died while the party wandered in the basin until finding water at the
Crooked River. Because of its climate, it received sparse white settlements and was largely left to the Paiute until the late 19th century. Settlement pressures and conflicts with the Paiute in other areas of Oregon caused President
Ulysses S. Grant in 1872 to create a
reservation for the Paiute encompassing Malheur Lake and much of the basin. Growing settlement pressures, in particular the discovery of
gold in the surrounding mountains, as well as the interest of white settlers to form ranches in the region, caused the
Commissioner of Indian Affairs to abruptly terminate the reservation in 1879. The Northern Paiute would survive virtually landless until obtaining tracts of land near Burns in 1935. The basin has a widespread decline in groundwater which has put the region at risk of ecological and economic collapse. Irrigation pumping is dropping the water table as much as every year in one area. ==See also==