Trinity Alps

On the ridge south of Sapphire Lake is an unusual phenomenon consisting of a temporary glacier, versus an inactive snowfield that melts out in dry years. Following years of heavy accumulation, an icefield appears in this fully sheltered north-facing cirque that can show active crevasses and seracs some tens of feet high. But this ice body, at an elevation of only 7,500 ft (2,300 m) in a region experiencing a long, hot dry season from about mid May to mid October, can disappear completely during a run of drier years.

Studies of lichen collars indicate that the site near Kalmia Lake is the snowiest spot in the State of California, receiving snow accumulation in excess of the Lake Helen snowcourse on Lassen Peak, by far the snowcourse with greatest late winter snow accumulation in California. This in turn is consistent with the fact of an active glacier under Thompson Peak, while, in contrast, no such active glacier exists under Brokeoff Mountain west of Lassen Peak, higher than Thompson Peak and presenting an ideal NNE-facing zone in the area of maximum snow accumulation beneath an almost-vertical cliff face 1,000 ft (300 m) high. Sufficient snow does accumulate under Brokeoff that in some years the snowfield there experiences incipient glacial motion. Two moraines below it, one very recent, provide clear evidence at least of mass transport in the recent past at that site. These moraines are quite a bit smaller than those found below the Thompson Peak glacieret.

The Trinity Alps section of the Klamath Mountains Ecoregion is botanically outstanding by having the second greatest number of conifer species of any place in the world. Russian Peak, in the Russian Wilderness just north of the Trinity Alps, has the greatest number of conifer species in North America.[4] So many genera and species of conifers exist together because the Trinity Alps are at the intersection of the Mediterranean climate of the south and the Northwestern coastal climate, which has a shorter dry season.

Northern tree species, such as subalpine fir (Abies lasiocarpa), Pacific silver fir (Abies amabilis), and Engelmann spruce (Picea engelmannii) are found here, as well as southern trees, such as incense cedar (Calocedrus decurrens), ponderosa pine (Pinus ponderosa), and white fir (Abies concolor), plus unique populations of foxtail pine (Pinus balfouriana) and weeping spruce (Picea breweriana).

Swift Creek viewed from a footbridge in July 2005

Other plants along the trails include the carnivorous California pitcher plant (Darlingtonia californica), the showy pinkish Lewisia cotyledon, and the rare Trinity Alps endemic wildflower Trinity penstemon (Penstemon tracyi). Sagebrush is found on ridges in the Scott Mountains.

Large fires have burned through some of the forests in the wilderness, including much of the 105,855-acre (428.38 km²) Iron/Alps Complex fire in 2008.

Most of the lakes have been stocked with rainbow, brown or brook trout, and some have self-sustaining populations. The major streams of the North Fork Trinity River and New River watersheds have spawning chinook salmon, and some have steelhead.

The Trinity Alps are home to much wildlife, including: American black bear, mountain lion, bobcat, blacktailed deer, lizards, chipmunks, and a great number of bird species. Deer and black bear are commonly seen. Less common but present are mountain lion, pine marten, fisher, and wolverine. Rough-skinned newts are commonly found in ponds and lakes. The Trinity Alps may be home to a cryptozoological phenomenon, the Trinity Alps Giant Salamander.

Geologically, the Trinity Alps consist of a mixture of igneous, granite and metamorphic peaks. In the eastern mountains are the Red Trinities, due to reddish ultramafic peridotite; in the central granitic batholith are the White Trinities; and in the western mountains are the Green Trinities, due to more extensive forest cover. The region contains much pine and fir forest as well as meadows, creeks, and lakes.