We took a 6 mile hike today (toward Breckenridge from Keystone and had a lovely view. The far off body of water is Dillon Reservoir.
The area had heavy pine beetle infestation and was being logged. Pretty cool machines!
Take a look at these videos (full screen is the best). Lifting, stripping, cutting, piling.
The stripping isn't as obvious as when there are green branches, but those trees all went behind the machine.