Strong evidence that spring is nearby has been found in a series of grizzly bear tracks in the interior of Yellowstone National Park.

The tracks were seen last Tuesday on Mary Mountain, which is in the middle of the lower loop of the park's Grand Loop Road a bit to the east of Madison Junction, park officials said. That area is good grizzly habitat, and the park routinely closes off human access from March into June along the Mary Mountain Trail from the Nez Perce trailhead to Mary Lake because of that.

Yellowstone officials point out that bears begin looking for food soon after they emerge from their dens. They are attracted to elk and bison that have died during the winter. Carcasses are an important enough food source that bears will sometimes react aggressively when surprised while feeding on them.

Park regulations require visitors to stay 100 yards from black and grizzly bears at all times. The best defense is to stay a safe distance from bears and use binoculars, a telescope, or telephoto lens to get a closer look.

Hikers, snowshoers, and cross-country skiers are encouraged to travel in groups of three or more, make noise on the trail, and keep an eye out for bears. Bear pepper spray has proven to be a good last line of defense, if kept handy and used according to directions when the bear is within 30 to 40 feet.

While firearms are allowed in the park, the discharge of a firearm is a violation of park regulations. Even the park’s law enforcement rangers who carry firearms on duty rely on pepper spray, rather than their weapons, as the most effective means to deal with a bear encounter.

Visitors are also reminded to keep food, garbage, barbecue grills and other attractants stored in hard-sided vehicles or bear-proof food storage boxes. This helps keep bears from becoming conditioned to human foods, and helps keep park visitors and their property safe.

Park officials ask that you report bear sightings to the nearest visitor center or ranger station as soon as possible.