as to preserve artifacts. Flora Rollins Pass consists of several distinct floral environments including lodgepole pine and quaking aspen at lower elevations, and krummholz at tree line. Above tree line, the landscape consists largely of small perennial wildflowers, cryptobiotic soils, and alpine tundra. The latter being extremely fragile and if damaged, can take 100–500 years to recover. Leaving the trail can cause erosion, land degradation, possible species extinction, and habitat destruction and it is for these reasons vehicles, including off-road vehicles, are not allowed to leave the established road. There are at least two marked revegetation areas on Rollins Pass: one at Yankee Doodle Lake; the other at the summit leading to the historic dining hall foundation. Pine beetle epidemic The mountain pine beetle epidemic, beginning in 1996 and continuing through present day, affects many forested areas in Colorado, including those on Rollins Pass. One out of every 14 trees in Colorado is dead. Trees affected by the beetles contain 10 times less water than a healthy tree and crown fires can quickly spread. Fauna The top predator in the area are black bears (Ursus americanus), generally below timberline; however, they occasionally venture above the krummholz. The bears prey on bighorn sheep (Ovis canadensis) and mountain goats (Oreamnos americanus), as well as yellow-bellied marmot (Marmota flaviventris) in the region. Above timberline, pikas (Ochotona princeps) are common. At or below timberline, both elk (Cervus canadensis) and mule deer (Odocoileus hemionus) are common. The presence of migratory bighorn sheep and other large game is the reason why Native Americans constructed sprawling yet intricate game drive complexes on Rollins Pass. The porcupine can be seen at all elevations on Rollins Pass, including at (and above) the summit. The porcupine begins its rounds at sunset, as it is nocturnal; this member of the rodent family also has the ability to adroitly climb trees. Among birds, the white-tailed ptarmigan (Lagopus leucurus) are present on Rollins Pass, especially above treeline. Their seasonal camouflage is effective in the summer against the exposed blocks of granite as well as against snow in the winter, rendering them virtually undetectable. Brown-capped rosy finches (Leucosticte australis), rock wrens (Salpinctes obsoletus), and pipits are also seen or heard at timberline and near the summit. Riparian zones Nutrient-rich ecosystems exist on Rollins Pass where water, and bodies of water, meet the alpine and subalpine tundras. Lakes There are three lakes on the west