Frontier Refinery has fire CHEYENNE, WY (wpr) - Authorities are trying to determine the cause of a fire and explosions that occurred at Cheyenne's Frontier Refinery. No one was injured in the fire that occurred a little before six in the morning in one of the Refinery's Crude oil units. An official says that unit suffered severe damage. The fire was put out in about an hour. © Copyright 2012, wpr