A recent study suggests the Jackson Lake, Harney Lake, Columbia, and Idaho springsnails, which a recent study suggests may all be the same species. The Jackson Lake, Harney Lake, Columbia, and Idaho springsnails have been identified as critically imperiled and in need of conservation. Already the Idaho springsnail is protected as an endangered species under the Endangered Species Act. The best available scientific information clearly demonstrates that the Jackson Lake, Harney Lake, and Columbia springsnails also need protection under the Endangered Species Act, whether individually or together with the endangered Idaho springsnail as one species.

Range of Jackson Lake springsnail (P. robusta), Harney Lake springsnail (P. hendersoni), Columbia springsnail (P. sp. A), and Idaho springsnail (P. idahoensis) as presented by Hershler and Liu (2004).

The Jackson Lake springsnail lives in cold springs and also in spring-influenced creeks and in Jackson Lake. The species prefers spring or spring-influenced environments with gravelly or rocky bottoms. The snail was historically reported from Teton County, Wyoming, from springs along the eastern edge of Jackson Lake, from springs around Elk Island within Jackson Lake, and from Polecat Creek, a tributary to the upper Snake River. Before 1994, the species had been reported from at least four sites.

Recent surveys have found the species to exist only in Polecat Creek, where the snail has been adversely impacted by competition with the nonnative, invasive New Zealand mudsnail and remains threatened by the nonnative snail. In discussing the impacts of the New Zealand mudsnail to the Jackson Lake springsnail in Polecat Creek, the Bureau of Reclamation reports, "The decline of a native species of snail (Pyrgulopsis sp.) was documented during the rapid population growth of New Zealand mudsnail in Polecat Creek, a tributary of Jackson Lake."

Populations in and around Jackson Lake are now extirpated, most likely as a result of modification of Jackson Lake by the Bureau of Reclamation. Although Jackson Lake is a natural lake, a dam and spillway have been constructed and the lake is managed for water storage and flood control. While historical sites have been inundated, in 1993 the lake was drawn down for dam repairs and the lake bottom was bulldozed and remolded, destroying the species' habitat and likely contributing to the extirpation of the species from Jackson Lake. Recent surveys have failed to relocate the species in and around Jackson Lake. The Bureau of Reclamation does not protect the snail.

The Jackson Lake springsnail was once a category 2 Candidate species, meaning the U.S. Fish and Wildlife Service believed listing was likely warranted, but that sufficient information did not exist to fully support listing. The species was dropped as a Candidate in 1996 due to the elimination of the category 2 Candidate designation, not because the species' status had improved or for other biological justifications. The Jackson Lake springsnail has clearly declined as a result of habitat loss and degradation, and currently survives in less than 25% of its former range and only at one location. The remaining population continues to face threats, and scientists have recommended the species be protected under the Endangered Species Act.

The Harney Lake springsnail occurs in small to large mildly thermal springs and spring pools that have moderate flow and are generally shallow. The springsnail was historically widespread in the Harney Lake-Malheur Lake area in central and eastern Oregon. Subfossil and fossil shells of the species have been found on the shores of Harney and Malheur Lakes, indicating a more abundant distribution in the recent past. The species is currently found at only four springs in the Harney Lake-Malheur Lake area of Harney County, Oregon and one spring site in the Lake Abert area of Lake County, Oregon.

Many springs that once supported the species are now dry, primarily as result of groundwater pumping. The species has disappeared from the location where it was originally discovered. Spring developments and domestic livestock grazing also threaten the species. Overgrazing is impacting all four populations of the species.

The Harney Lake springsnail is currently ranked G1 by the National Heritage Program, meaning it is critically imperiled throughout its range and at great risk of extinction. The species has clearly declined because of habitat loss and degradation and currently survives in a fraction of its former range. Because of population declines, habitat loss and degradation, the species' limited occurrence, and ongoing threats, scientists have recommended the Harney Lake springsnail be protected under the Endangered Species Act.

The Columbia springsnail is a recently discovered species and was named Pyrgulopsis new species 6 by scientists. The Columbia springsnail is found in the lower and middle Columbia River in Oregon and Washington in deep water river habitats with rocky substrate and constant flow. The snail exists in areas that are most similar to what the Columbia River was like before it was dammed. The historical population size and distribution of the snail are not known since the species was only recently discovered. However given the snail's habitat needs, it is believed the population was once ubiquitous in the lower Columbia River from the eastern Columbia Gorge to Wallula Gap. The species is currently known from only six sites.

Population declines are attributed to dams on the Columbia River, which have destroyed and degraded much of the species' habitat throughout its range. Surviving populations are threatened by siltation caused by dams, water pollution, stream channel modifications undertaken to facilitate river navigation, and the nonnative, invasive New Zealand mudsnail.

The Columbia springsnail is currently ranked G2, meaning it is critically imperiled throughout its range. The species has declined because of habitat loss and degradation and currently survives in a fraction of its former range. While once thought to be widespread, the species now is known only from six isolated locations, all of which are suffering from habitat loss and degradation. Because of population declines, habitat loss and degradation, the species' limited occurrence, and ongoing threats, scientists recommended listing the Columbia springsnail under the Endangered Species Act.

The Idaho springsnail, which exists only in the Middle Snake River of southern Idaho, is presently protected as an endangered species under the Endangered Species Act. The species has declined significantly and its range has been reduced by nearly 80%. The species was historically collected from 10 sites, but is currently known with certainty from five sites. Habitat loss and degradation throughout the species' range has led to population declines. The snail depends on cold spring-influenced environments in the Snake River with sandy and sometimes gravelly substrates, which have been degraded by siltation, agricultural pollution, and dams. The invasion the nonnative New Zealand mudsnail is a significant threat to the snail.

Most recently, the U.S. Fish and Wildlife Service gave permission to the Idaho Power Company to operate dams along the Middle Snake River in such a way that would adversely impact the Idaho springsnail and its habitat. Scientists have flatly criticized this decision because of the adverse impacts to the Idaho springsnail. Operation of dams on the Middle Snake River also promotes the spread of the New Zealand mudsnail and degrades water quality, both of which are significant threats to the Idaho springsnail.