Fall is speeding our way, and for wildlife, that means it's time to pack on the calories. In western national parks such as Yellowstone, Grand Teton, and Glacier, bears are on the prowl looking for some good meals.

In Yellowstone officials are warning visitors to be mindful of grizzlies, as this year's crop of whitebark pine seeds -- a meal that packs a lot of calories for the bears -- was poor. As a result, park officials expect to see "an increase in human-bear encounters in the backcountry this fall as bears seek alternative foods common at lower elevations."

"In the last week, (national) park and Forest Service officials have observed a significant increase in bear activity at lower elevations near trails, roads, and developments where bears are foraging for berries, bison carcasses, digging ant hills, and ripping open logs for ants," Yellowstone officials said in a release. "Berry production has been especially good this year. In addition, apple trees have been highly productive this year. However, since berry producing shrubs and apple trees are generally found at lower elevations more frequently inhabited by people, we expect human-bear encounters to be more common this fall."

So whether you're out enjoying a day with friends hunting on national forest lands or hiking elsewhere on public lands, remember to follow food storage guidelines. These guidelines have been in place for many years in Yellowstone National Park, the Gallatin National Forest, and the Beartooth Ranger District of the Custer National Forest and are intended to help keep both you and bears safe.

* When hiking on national park lands or hiking or hunting in national forests, carry bear spray, hike in groups of three or more people, be alert for bears at all times, and make noise so you don’t surprise bears. If you encounter a bear, do not run, slowly back away to put distance between you and the bear. This often diffuses the confrontation. If the bear charges, stand your ground and use your bear spray. In most cases the bear will break off the charge or veer away. If the bear makes contact, drop to the ground face down on your stomach, with your hands clasped behind your neck and lie still. Make sure the bear is gone before moving.

* When camping in the backcountry, hang all food and garbage from food storage poles or bear boxes that are provided at every Yellowstone backcountry campsite and some national forest campsites. Food should be hung at all times except during preparation and consumption. If a bear approaches your campsite, yell and bang pots, pans, or other objects to discourage it from entering.