DENVER -- Bill deVergie knows firsthand what it's like to hit a deer.

"I've hit them in my division truck, but I hit one in the family Aerostar," said deVergie, a regional biologist in Montrose. "We were driving along at about 45 mph when this deer suddenly bounded out from the side in front of the vehicle. I hit it head-on and did $3,000 damage to my minivan."

DeVergie is not alone.

During the past five years, the number of accidents involving wildlife in Colorado has risen 83 percent, from 2,237 in 1999 to 4,089 this past year.

Wildlife officials aren't sure why.

"Right now, we're really having problems on U.S. 550 south of Montrose to Ridgway with cars hitting deer," deVergie said. "With some financial help from Safari Club International, we put up a number of large signs that say, 'Caution. Migrating deer on highway. Please be alert. Please slow down.' It has a picture of a deer in the center of it."

"Some of it is due to the drought because wildlife hang closer to the barrow pits where the grass greens earlier in the season," said Todd Malmsbury, spokesman for the state Division of Wildlife. "They are only a couple of steps from traffic."

But there must be other factors that come into play as well because the number of accidents has fluctuated and hasn't risen at a steady rate.

Master Trooper Ron Watkins of the Colorado State Patrol said that five years ago, 10 percent of the accidents handled by the patrol involved vehicles hitting animals.

Today, it has risen to 13 percent.

"The causes are varied, but most come down to an increase in traffic and an increase in speeds," Malmsbury said.

Dan Prenzlow, area wildlife manager in Meeker, said the majority of bad accidents are caused by people jerking the wheel while trying to miss an animal and rolling their car.

"It's a lot better to hit a deer, or even an elk, than it is to roll," he said.

Prenzlow said he's learned not to panic when a deer bolts out. Brake, try to steer gently away, and more often than not, the deer ends up running into the side of his truck.

"They don't do as much damage when they hit you," he said.

National insurance reports indicate there are more than 500,000 collisions between vehicles and animals annually that kill more than 150 people and injure 10,000 others.