It doesn't even take a comet. When we lived in Valdez, we were continually hacking back the wilderness that encroached on our property. Willows, elder, alder, and cottonwood had to be repeatedly ripped out and removed. Anything man can build in the wilderness, he can destroy. A few good bulldozers here and there could take out the pads and remove the roads. Nature in Alaska is particularly aggressive, one reason why it remains a wilderness. Most people just don't have the stamina to keep pushing it back.