Tall trees and deep shadows give Tioga Road an air of mystery as it rises from Crane Flat and leads drivers east toward the park's high country. Posted speed limits — 35mph in some stretches, 45 in others — are constant reminders that animals suddenly can appear, sometimes with fatal consequences.

The road is an interruption to their environment, says Steve Thompson, the park's branch chief for wildlife management. Some animals are unwilling to cross the road's open space. Others cross often and even learn to stay back when cars are coming.

"It's not uncommon to see mule deer along the road, and occasionally a bear," he says. "In the park, we lose up to a dozen bears in collisions with automobiles every year, and that doesn't include those that are struck and crawl off and we don't know their fate."

Animals are most active in the twilight of early morning and late evening, Thompson says. Meadows are good areas to spot wildlife, but animals can show up anywhere on the road without warning.

"Whenever a bear appears, it can create a traffic jam," he says. "It tends to bring cars to a screeching halt. Some bears flee at the sight of people, but others show no fear, although we wish they would."

Deer migrate to the high country in summer on a route that parallels the road. Bears also move about, eat- ing grass in the spring and berries and acorns later in the year. They also rip apart dead trees in search of termite and ant larvae, and are at- tracted to dead animals on the road.

"We try to locate roadkills and drag them off as soon as possible to keep bears off the road," Thompson says. "The number of roadkills could be reduced if people would slow down."