The federal grizzly protections have proved successful, and the grizzly population in the Yellowstone area has grown to roughly 700 after only 136 bears existed in 1975. Accordingly, scientists think the population may be at capacity in the region. In the last two years, though, researchers have accounted for 106 grizzlies killed in the Yellowstone area, accounting for the highest number of deaths over such a time period since the ursine omnivore listed as threatened in 1975. Despite those totals, however, U.S.F.W. Assistant Regional Director Michael Thabault said the population is sustainable after growing from only 136 area bears when they first received protections.