The number of brown bears in Yellowstone continues to grow. This year officials are putting the population at 603 bears which is the highest level in decades. According to a USA Today  article:
Our population is strong, our counts of females are high," said Chuck Schwartz, a U.S. Geological Survey scientist who heads the Interagency Grizzly Bear Study Team. "Right now, all indications are we haven't turned into negative trajectory."
Schwartz added that the 603 population figure was a conservative estimate and that the true number could be significantly higher.
However the increased level of bears has also created more human bear encounters with two people killed by grizzlies this year alone. Just last week a deer hunter in the South Fork area killed an attacking grizzly  in self defense.