ID: LEMHI CO. 2255 M.
General Description.—Guilday and Adam 1967: Also known as Cave no. 2. A small cave ca. 10 m long, 6-8 m wide, 2-3 m deep. At mouth of Indianhead Canyon, W flank of Beaverhead Mts. (a southern spur of the Bitterroot Range), SE Lemhi Co., Sec. 13 or 14, T11N, R30E (44°17' N, 112°35' W), 7400 ft. Two hearths midway in the deposits indicate man occupied the cave in the past. Kurtén and Anderson 1980: Cave self-sealed ca. 9000 BP. Guilday and Adam (1967) cite Dort et al. (1965) as believing the cave was sealed by Climatic Optimum time. Akersten and McCrady (1990) say that a re-evaluation of cave size, morphology, and stratigraphy and taphonomy of the fauna indicates the cave was a carnivore, primarily canid, denning site rather than a human occupation site. They reexcavated a portion, finding rare extinct megafauna with abundant microfauna below all evidence of cultural activity.
Age.—11,580 ± 250 (GX-395) (Willig and Aikens 1988: hearth date; also present, a flaked antler tine with cut marks); 10,370 ± 350 on charcoal from ca. midway in the deposits. Guilday and Adam (1967) cite Dort et al. (1965) for dates. Latter source also for citation that probably infill began at the onset of Anathermal times, corresponding to the beginning of the recession of the Pinedale glaciation.
Environment.—Guilday and Adam 1967: Quotes Sadek-Kooros (1966) as Indian Head now a dry canyon with no surface flow in recent time. She believes that the increase in precipitation during the Neoglacial was insufficient to provide surface runoff. Birch Creek runs S toward the Snake but originally disappeared into sinks ca. 30 mi S Jaguar Cave. Site dry, being in rain shadow of Lemhi Range. Forty miles SW of Jaguar Cave, precipitation averages 9.25" per year. For middle 10 miles of the valley, Birch Creek lined with Betula, Salix, and grassy, streamside vegetation. Upper 10 mi of valley swampy until drained (volcanic dike raises base line, though breached at the "Narrows"). Valleys dry, covered with Artemisia and scattered, low pines (Pinus) where the canyon mouth emerges from the mountains. Guilday and Adam 1967: Average July temperature = 66.8° F, average Jan., 16.9°. Evidence of glaciation plentiful. They cite Dort (1965) as it being possible to identify three Buffalo glaciations, separated by intervals of canyon cutting, two Bull Lake advances, several Pinedale advances and recessional still-stands, and at least six subdivisions of Neoglaciation in the Lemhi and Beaverhead mountains.
Paleoenvironment.—Guilday and Adam 1967: Two aspects of fauna striking: no arboreal or woodland forms (except marten, known to wander and to inhabit talus rather than woodland at times) and absence of any species now occurring south of the site. Other faunal evidence seems to agree with a lack of forest cover. They note particularly Dicrostonyx as an obligatory tundra form. Akersten and McCrady (1990) note that the fauna suggests an extreme compression of life zones in this mountainous region and that the evidence indicates the modern, native small mammals coexisted during the late Pleistocene with the extinct fauna and a few northern forms during the late Wisconsinan. Guilday and Adam 1967: Note that Dicrostonyx and Lagurus are the only microtines in lower levels; they believe the association may be valid even though the two are not sympatric now.
Comments.—Guilday and Adam (1967) list Vulpes cf. macrotis without comment, yet not known from that part of Idaho— from much farther to the southwest— they state that one of dominant features is absence of any species that occur south of the site at present. Thus appears likely that either a lapsis for velox or that they were considering them conspecific with the name macrotis applicable.
Publications.—(*Akersten and McCrady 1990); Butler 1978; Dort 1965, 1975; Dort et al. 1965; (*Emslie 1985c); (Frison, Walker, Webb, and Zeimens 1978); (*Guilday and Adam 1967); Harris 1985; Kurtén and Anderson 1972; Lawrence 1967; L. Miller 1965; Sadek 1965; Sadek-Kooros 1966; Swanson, Butler, and Bonnichsen 1964; (Willig and Aikens 1988); Wright and Miller 1976.
Last Update: 19 August 1998.