Binney (1886) treated all morphological variants of this species (along with several other currently recognized species) as "varieties" of Patula strigosa (= Oreohelix strigosa).
In the early literature oquirrhensis, gabbiana, utahensis, hybrida, and hemphilli were recognized as subspecies of Oreohelix haydeni under an antiquated concept of subspecific taxonomy. Later authors (e.g., Henderson and Daniels 1916, 1917) suggested that these were merely named color forms.
Chamberlin and Jones (1929) referred to a subspecies wasatchensis. Apparently this was an error, because wasatchensis was never proposed as a subspecies of Oreohelix haydeni but is recognized as a subspecies of the related Oreohelix peripherica; the context in which this apparent error occurs suggests that an inadvertent substitution was made, replacing the intended name oquirrhensis with wasatchensis.
Pilsbry (1939) retained three taxa as valid subspecies occurring in Utah: haydeni, oquirrhensis, and corrugata.
Status in Utah
Approximately 21 colonies have been reported in Utah. Determination of whether some clustered localities are, as Henderson and Daniels (1917) thought, separate colonies or are large continuous colonies will require new field work.
The distribution of this species in Utah is somewhat patchy and scattered through Cache, Rich, Weber, Morgan, Salt Lake, and Tooele counties.
One seemingly anomalous report is available from Washington County, which prompted Vanatta (1921) to predict statewide occurrence of this species, specifically the subspecies oquirrhensis. Woodbury (1929) and Gregg (1940) considered this record to be erroneous.
At 5 localities described by Henderson and Daniels (1917), the terms "plentiful" or "common" were used to describe populations. Several colonies were reported to be declining (Henderson and Daniels 1917), and no recent efforts have been made to verify their continued existence.
Clarke (1993) conducted surveys at the type locality for the type race, haydeni, and also at the type locality for the race corrugata. At the former locality, he estimated a population of 1 million snails within the 60-acre colony despite the fact that only 10 live snails were recorded on his field sheets. He did not explain how he derived this estimate. At the type locality for corrugata, the population was estimated to contain between 1 million and 10 million snails. Again, Clarke did not explain how this population estimate was calculated; only 6 live snails were recorded on field sheets after searching 100 acres.
As early as 1915, Henderson and Daniels (1916) noted habitat degradation at several of their localities. Describing the poor conditions near Garden City, Henderson and Daniels (1917) stated: "[t]he slopes are now very barren, but we were informed by pioneers that forty-five years ago they were well covered with large mountain mahogany, up to a foot in diameter[.] ... [W]asteful cutting and fires have denuded the hills for some miles back, and overgrazing by stock has been disastrous to the smaller shrubs and herbs."
Near the type locality of Oreohelix haydeni haydeni, Henderson and Daniels (1917) commented that "[t]he vicinity is covered by a thick coat of lime dust from the cement plant. It is strange that any live examples were found under the circumstances." Clarke (1993), who investigated the same area 76 years later, listed grazing and "expansion of quarry activities" as a threats to the colony. Declining habitat quality could have taken a toll in the intervening years, however, because Clarke (1993) apparently did not find the species haydeni to be as common in this portion of Weber Canyon as Henderson and Daniels (1917) had.
Natural catastrophic events can also affect colonies. At least one colony appeared to have been extirpated by fires in years immediately preceding surveys by Henderson and Daniels (1916, 1917). Drought can exacerbate anthropogenic effects, increasing erosion (see Henderson and Daniels 1917) and also influence the frequency and intensity of fires.
Clarke (1993) did not note evidence of declines in either of the two colonies that he visited. Henderson and Daniels (1916, 1917), however, described severe habitat degradation at several of the localities visited. Noting the combined effects of deforestation, fire, and overgrazing at a locality near Bear Lake, Henderson and Daniels (1917) stated that "[e]rosion is rapidly carrying the soil and vegetative debris from beneath the scant shrubbery and may soon destroy the colony, unless saved by a series of years of increased moisture ...." A colony near Logan was said to be "likely near extinction" from the effects of overgrazing and subsequent erosion (Henderson and Daniels 1917).
Most known localities have not been revisited since 1916. Field work is necessary to determine the current status of colonies throughout the range of Oreohelix haydeni.
Habitats Utilized in Utah
Henderson and Daniels (1916), referring to the genus Oreohelix in general, state: "Limestone is common at almost every locality visited, this being a favorable condition for Oreohelix. The edges of coarse, angular limestone talus protected from rapid evaporation by overhanging bushes, formed the cover for some of the finest colonies we have seen, the snails occupying crevices among the rocks." Indeed, the majority of their localities for Oreohelix haydeni fit this description. The few localities where exposed limestone was not present were presumed to have calcareous soils.
Common vegetative cover for this species included balsam root (Balsamorhiza sp.), bitterbrush (Purshia tridentata), mountain maple (Acer sp.), sagebrush (Artemisia tridentata), and wild cherry (Prunus sp.) (Henderson and Daniels 1916, 1917).