High Country News' recent article on how beavers shaped the West, "Voyage of the Dammed," (great headline) surprised me -- and some commenters -- with its estimate of pre-fur trade population figures.
Historical trapping records in the Colorado Rockies show "60 to 80 beaver" per mile of stream, says Trey Schillie, an ecosystem services analyst for the U.S. Forest Service's Rocky Mountain Region. That abundance was repeated across the West.
Castor canadensis, believe it or not, is a time shifter. The humble, hardworking rodent, through its dams and ponds, can extend the release of water late into summer, saturating the ground and healing watersheds. It has the power to re-create the primordial, wetter West that existed for millennia -- a West we just missed seeing.
We had some beavers on our creek--they seem to have moved downstream, after eating all the willow and narrowleaf cottonwood that they could get near their lodge.
Their dam "encroached" on some neighbors' lawn, so eventually they breached it -- after the beavers were gone, I want to think.
Everyone else was pleased to see them, if only for the thought that the dam (still holding back some water) would raise the water table and hence help our wells.