Back in the 1950s, when the same problem emerged, historian Bernard DeVoto proposed a drastic remedy. "Let us, as a beginning, close Yellowstone, Yosemite, Rocky Mountain and Grand Canyon National Parks — close and seal them, assign the Army to patrol them, and so hold them secure till they can be reopened. They have the largest staffs in the system but neither those staffs nor the budgets allotted them are large enough to maintain the areas at a proper level of safety, attractiveness, comfort or efficiency."