Sgt. Steve Shea told The Vancouver Columbian officers decided to kill the animal Tuesday because it could have caused a collision on a road.
The escaped bull was running around Whipple Creek Regional Park.
The owner tried putting grain in a can and shaking it, but the bull allowed her to approach to only about 20 feet before bolting.
A Ridgefield woman riding a horse at the park tried to corral the bull but her horse spooked and bucked her off.
After the bull was shot, a rendering business pulled the carcass to the road and skinned it.