National Farmers Union Property and

MAUGHAN, Justice: Plaintiff insurer initiated this action seeking contribution from defendant insurer as a co-insurer. 1 Both parties moved for summary judgment, defendant's motion was granted. Plaintiff appeals seeking judgment in its favor. The judgment of the trial court is affirmed. Plaintiff issued a liability policy covering the Weber County Sheriffs Mounted Posse, on their drill grounds. The policy provided under the liability provision: