Common Name
EUREKA MOUNTAINSNAIL

Scientific Name
OREOHELIX EUREKENSIS

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Utah Taxonomy

This taxon was originally described as Oreohelix hemphilli eurekensis by Henderson and Daniels (1916); it was subsequently elevated to full specific status as Oreohelix eurekensis by Henderson (1924).

Two races of Oreohelix eurekensis are recognized, Oreohelix eurekensis eurekensis, the type race described by Henderson and Daniels (1916), and Oreohelix eurekensis uinta, a race proposed by Brooks (1939). The latter taxon was treated as a full species by Turgeon et al. (1988), but, "[i]n the absence of a published justification for that taxonomic change", Turgeon et al. (1998) returned uinta to subspecific status. Roscoe (in Roscoe and Grosscup 1964) expressed "grave doubts as to the validity" of uinta, even as a subspecies.

Status in Utah

Endemic to Utah, this species has been reported from about 6 localities representing 4 widely separated populations scattered across northern Utah roughly in an east-west band. These 4 populations are in the northern part of the East Tintic Mountains (Mammoth Peak, Godiva Mountain, and Lime Peak), on the Juab-Tooele county line (Henderson and Daniels 1916, 1917, Clarke 1993, Clarke and Hovingh 1994); on Hominy Creek on the south slope of the Uinta Mountains, near the Duchesne-Uintah county line (Brooks 1939, Oliver and Bosworth submitted); in the Deep Creek Mountains, near the Juab-Tooele county line and the Utah-Nevada boundary (Roscoe 1954); and on the East Tavaputs Plateau, Grand County (Roscoe and Grosscup 1964).

In the original report of this taxon, Henderson and Daniels (1916) wrote that they found "7 specimens, all dead shells," at the type locality in 1915. However, when they revisited this site in 1916 (Henderson and Daniels 1917), they found "about 600 [Oreohelix eurekensis], mostly alive." A recent estimate of the population of this species at the type locality and vicinity was 50,000 to 500,000 individuals on Mammoth Peak and Godiva Mountain, with perhaps a very small population on Lime Peak (Clarke 1993, Clarke and Hovingh 1994); this estimate was based on the finding of a combined total, from the three mentioned localities, of only 48 dead shells and 3 live individuals and appears to be a gross overestimate. It seems much more reasonable to conclude, from the recent finding of a total of only 48 dead shells--some (perhaps many) of them old--and 3 live individuals (all on Godiva Mountain), that the actual total population of this species in the vicinity of the type locality is less (perhaps much less) than one-tenth the number(s) estimated by Clarke. It is indeed difficult to envision the formula used to arrive at an estimated living population of 50,000 to 500,000 from a field census that revealed only 3 living individuals. New information concerning the population of Oreohelix eurekensis uinta is forthcoming (Oliver and Bosworth submitted).

The principal threat to this species at the type locality is mining activities. Clarke (1993) pointed out that "[t]he whole area [inhabited by this species] is covered by patented mining claims controlled by the Kennicott [sic] Copper Company." He noted as well that "Godive [sic] Mountain has several abandoned mines on it and these, or others, could be activated if proper economic conditions develop", and "[m]ining operations, now abandoned, have reduced the available habitat for this species". On the field sheet for Godiva Mountain, he reported: "Area to two-thirds way up mountain has been seriously disturbed by mining activities (slag heaps, trash piles, areas flattened by vehicles, 2 excavations)...." Clarke also considered fire to be a potential threat to this species. Oliver and Bosworth (submitted) discuss threats to the race Oreohelix eurekensis uinta.

Clarke and Hovingh (1994) stated: "Although we did not find the large population of this species seen on Godiva Mountain by Henderson & Daniels (1917), our findings there are quite similar to their earlier findings (Henderson & Daniels, 1916). Our work also materially extended the known range of the species [to Mammoth Peak and Lime Peak]. We therefore believe that no general population decline has occurred." This statement must be viewed skeptically: Only on Godiva Mountain, Henderson and Daniels' type locality, did Clarke and his co-workers find any living individuals of this species--and there only 3. In the 2 areas that "materially extended the known range of the species", Mammoth Peak and Lime Peak, they found only dead shells. In fact, on Mammoth Peak, while searching for Oreohelix eurekensis but finding only dead shells, they found 23 living snails of a related species, Oreohelix strigosa, which shows that both the sampling techniques that were used and the climatic conditions at the time were appropriate for finding living snails of the genus Oreohelix. Moreover, on Lime Peak their search yielded only "1 old shell", and it should be recognized that old shells often are very old--hundreds, if not thousands, of years old. Thus, while it is clear that this species has inhabited Mammoth Peak and (probably) Lime Peak at some time in the past, there is no convincing evidence that an extant population of this species is present at either of these sites that "materially [extend] the known range of the species." Thus, Clarke and Hovingh's (1994) failure to find the large population of this species discovered earlier in this century on Godiva Mountain, where they found only 3 living individuals, should be considered, at least until a more thorough inventory for this species is conducted, as evidence of a population decline--perhaps a very serious one.

Inventory is needed to resolve questions regarding the health and extent of the Godiva Mountain population as well as to establish whether these snails survive on Mammoth Peak, where only dead shells have been discovered thus far, and similarly to determine whether the species is present on Lime Peak, from which only 1 old shell is known. Although Clarke (1993) surveyed additional sites in the East Tintic Mountains without finding this species, further prospective searches should be conducted.

It is also possible that this species could be detected elsewhere in northern Utah, an opinion expressed strongly by Roscoe and Grosscup (1964), who wrote: "The species [Oreohelix eurekensis] is undoubtedly widely distributed over both the Bonneville and Colorado drainages in favorable situations."

Habitats Utilized in Utah

Henderson and Daniels (1916), in the type description, mentioned that this snail was found "associated with O[reohelix] cooperi [= Oreohelix strigosa]" "on north side of Godiva Mountain, ... on a slope of Paleozoic limestone, under shrubs and other vegetation ... [and] angular blocks of limestone, no good rock slides exposed." Clarke (1993), discussing this same locality and population of Oreohelix eurekensis, reported that the species is "[f]ound under pygmy sagebrush and at the bases of ledges on north-facing slopes at altitudes of about 2200 to 2400 meters."

Roscoe (1954) reported this species "at base of cliff, south side of canyon bottom, ... [i]n Aspen, Douglas Fir forest, el. ca. 7500 feet."

Roscoe and Grosscup (1964) found this species at elevations of "about 8025 feet" and "about 8000 feet" "at the base and trunk of aspen trees" and "on dead leaves at the base and trunk of aspen". They (Roscoe and Grosscup 1964) noted: "All of the rock exposures in the area are of a yellowish sandstone, presumably part of the Eocene Green River formation." At the 2 sites where they found Oreohelix eurekensis, "the forest cover includes aspen, spruce, pine, and fir [while] [t]he valley floors and other open areas are grassy, with interspersed stands of sagebrush [and] [j]uniper and scrub oak occur sparingly."

Information concerning the habitat of Oreohelix eurekensis uinta is being reported by Oliver and Bosworth (submitted).

Sources:

  • Text modified from: Oliver, George V. and William R. Bosworth III. 1999. Rare, imperiled, and recently extinct or extirpated mollusks of Utah[:] a literature review. Publication number 99-29. Utah Division of Wildlife Resources, Salt Lake City. 230 pp.

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