A new study shows that natural land in the American West is diminishing at a faster rate than anyone could have expected:

"From 2001 to 2011, an area totaling 4,321 square miles -- or 15 times the size of San Jose, Oakland and San Francisco combined -- was modified by development in the 11 Western states, the report found, with California losing the most natural land, and Wyoming and Utah changing at the fastest rate.

"We are nibbling away at our wild places at a fairly rapid clip," said Mike Dombeck, former chief of the U.S. Forest Service and the U.S. Bureau of Land Management in the 1990s ...

... Their conclusion: Every 2.5 minutes the West loses an area of natural land the size of a football field to human development. And each year, on average it loses 432 square miles, an area nearly the size of Los Angeles."