SACRAMENTO – Federal wildlife officials say the California red-legged frog needs four times as much protected habitat than was set aside for it two years ago.

The decision was announced Tuesday and greatly expands protections for the frog, which listed as a threatened species in 1996.

It's the result of an investigation last year that found a former Interior Department official had pressured government scientists to alter their findings on endangered species.

The latest proposal from the U.S. Fish and Wildlife designates 1.8 million acres in 28 California counties as habitat that is critical for the frog's survival.

The frog, the largest species native to the western U.S., is believed to have inspired Mark Twain's tale, “The Celebrated Jumping Frog of Calaveras County.”