The Center for Biological Diversity (CBD) calls the American pika (Ochotona princeps) a "canary in the coal mine" when it comes to global warming. Typically found on scree and talus slopes in alpine areas above treeline, this little (Guinea pig size) tail-less Lagomorph (member of the rabbit family) is often called the rock rabbit, cony, and mouse hare.
Anyone who has spent a little time hiking or backpacking in the Rockies knows the pika. They dart in and out of the boulders, cut grasses and forbs in the meadows and carry it back to their haypiles, and chirp out their alarm call when you come too close. If you sit down and remain quiet for 15 minutes or so, they will resume their business and come within a few feet of you.
The CBD has sued the US Fish & Wildlife Service to list the pika under the Endangered Species Act. This is a new legal approach, and would force the government to deal with the challenge of global warming. Global warming harms pika in several ways: (1) they are very temperature sensitive, and cannot survive at temperatures above 75 to 80 deg F; (2) on a warm day in the high country, they must retreat into their dens, and have less time to gather food; (3) the heavy snows of winter insulate them from harsh, cold temperatures; (4) the forbs and grasses they eat are very sensitive to hot, dry weather.
Over the past decade or so, many populations of pika have already winked out, and the survivors have moved higher and higher up the mountain slopes. Because pika live as island populations in high peaks areas, they also seem to have evolved into a large number of genetically distinct subspecies (map from CBD):

Sources:
Center for Biological Diversity press releases, http://www.biologicaldiversity.org/swcbd/press/american-pika-08-21-2007.html and http://www.biologicaldiversity.org/swcbd/search.html.
Denver Post article, http://www.denverpost.com/breakingnews/ci_7963405 .
Entry for American Pika on Wikipedia, http://en.wikipedia.org/wiki/American_Pika .
The area's height and location help in capturing a lot of snow. Even in the driest and hottest of summers, the big snow cornice along Saddle Ridge lasts all summer long, as does the glacier along the upper lake. Yes, it is a true glacier, and the only one in the Pintler, according to Don Nyquist, a National Weather Service observer, meteorologist, and Anaconda resident. Don says a key characteristic that makes this a glacier is the formation of firn--"the metamorphic layer of dense, granular snow between the accumulation area (new snow) and glacial land ice." Here's a photo of the upper lake and its glacier (West Goat Peak is on the far right of the snow cornice just below the ridge):
The approach to West Goat Peak is very pleasant with very little scree (as Pintler peak bagging goes). Here's Don picking his way along the ridge, with the fantastic vertical goat cliffs on his right:
Just as we finished supper that evening, a big thunderstorm swept through. This is why I prefer to camp down in the timber, and not on the barren ground around Lost Lakes. As RTD and I lay in the tent watching through the vestibule door as lightning flashed and crashed, I took a moment to appreciate the difference between Pink Mountain Heath (Phyllodoce empetriformis):
Time to head down. On approaching the meadow, RTD began an intense gaze toward a spot about 300 yards below us. I've learned to trust her sharp eyes. What's this big-assed creature flipping over rocks (lower right in photo)?