The U.S. is 2.3 billion acres in size. The Federal government owns 30% of the total, more than two-thirds of a billion acres.
The Feds own more than fifty percent of Alaska, Arizona, Idaho, Utah and Wyoming. The Federal government owns nearly all of Nevada (over 90%) and nearly half (47%) of California.
Is that enough for all the environmentalists to live on? It is four acres per environmentalist. It would take fifteen minutes to walk around each environmentalist's property if it were flat desert. (Table 348, pp222).