These metamorphic rocks on the Blue Ridge tend to be very erosion-resistant, meaning they don't weather at the same rate as the rocks found in places like the High Knob summit. As a result of this resistance and the incredible uplifting forces at work during the mountains' infancy (Mt. Rogers and Whitetop are actually found on long-dead volcanoes), mountains in this region tend to reach incredible heights for the eastern U.S. Mount Rogers, for example, soars to 5,728 feet above sea level as the highest point in the state.

 

This height does more than just create a superlative for the state, though. High mountains tend to be remarkably cooler and, in some cases, wetter than areas surrounding them. As a result, high summits like those found on Mount Rogers tend to have totally unique forest types compared to the rest of the mountains. Mount Rogers's summit, for example, is cloaked in a dark evergreen forest made up of Red Spruce and Frasier Fir (see the photo with his placeholder) - tree species found most commonly in much cooler and wetter habitats than those found in the southern Appalachians. Red Spruce, in fact, is typically only found in New England, Canada, and states across the far northern U.S., while Frasier Fir is found nowhere else on Earth outside of the Southern Appalachians!

 

What is going on to allow these species to persist here? Our understanding of the history of Appalachian spruce-fir comes, unbelievably, from the space inside the skull of a musk-ox (a now-extinct species) discovered at the bottom of an ancient bog near Saltville, Virginia in 1967. Scientists discovered pollen grains from spruce inside this musk-ok and surrounding soils, suggesting that, at some point in the past, spruce-fir forests must have occurred at lower elevations and not just on high peaks like Mt. Rogers. What happened? During the time when that musk ox was alive, around and before 10,000 years ago, North America was experiencing the Wisconsin Glaciation, a time period when massive ice sheets covered our northern states and temperatures were much cooler than they are at present. This enabled the spruce-fir forests to thrive at lower elevations.

 

As our climate warmed and transitioned out of this glaciation, organisms adapted to cooler climates moved north and, here in the mountains, up! Today, our once-abundant spruce-fir forests are isolated in "refugia" on our uppermost summits, where conditions are still relatively suitable for survival. Along with the spruce-fir forest, other organisms have become “trapped” in these high elevation habitats. Since these organisms are isolated, they are nearly all considered globally rare.  These include the unique pygmy salamander, the rare Weller’s salamander, the miniscule northern saw-whet owl, and the northern flying squirrel, among others. These unique species make Mt. Rogers and other spruce-fir forests much more than scenic viewpoints; these peaks are instead unique, ecological "islands" in the sky!