Federal and state wildlife agencies have launched a campaign to decrease the number of grizzly bear killings in the greater Yellowstone region after a record number of deaths last year.

More backcountry ranger patrols are planned, thousands of warning signs will be posted and hunters and hikers will be encouraged to use pepper spray instead of firearms when approached by a bear.

The Yellowstone region's 600 grizzlies were removed from the endangered species list in 2007. It remains illegal to intentionally shoot the animals.

Forty-eight bears were killed by humans last year, out of 79 total grizzly deaths. If the death rate stays high for a second consecutive year, that would trigger a review of the bear's endangered status.

Seventeen grizzlies have died so far this year.