Three people in the truck were also hurt, The Denver Post reported. They included one injured when the vehicle crashed into a tree and a woman bitten by a dog.
Denver Police Chief Robert White said the chase began when officers recognized a red pickup sought by authorities in suburban Adams County. By the time the truck crashed, dozens of police cars were in pursuit at speeds that reached 60 mph in a residential neighborhood.
A witness described a man in the bed of the truck holding a gun and throwing computer parts and hubcaps at the pursuing cars.
"I just saw the gun in his hand, and that's when I started yelling at the kids," Rosa Bonilla said. "He was sitting down. He had the gun in his right hand. He looked like he was trying to reload it."
The wounded officer was identified by police sources as Sgt. Robert Motyka. White said the officer was "going to be OK" and was in "good spirits."