Nassau and Suffolk police are offering a reward of up to $15,000 for information leading to the arrest of a serial gas station robber linked to 15 holdups.

Police say the crime spree stretches a 60-mile span from Elmont to Riverhead. Authorities have been tracking the pattern since August. Nine of the robberies were in Nassau County, and the other six were in Suffolk.

Suffolk and Nassau officials say the armed robber always wears a hat and hides his gun under a cloth. The holdups have been at night.

The suspect is considered armed and dangerous.

Anyone with information can contact Nassau County Crime Stoppers at 1-800-244-TIPS or Suffolk County Crime Stoppers at 1-800-220-TIPS.

Nassau officials say they will have patrol cars visiting gas stations throughout the county to make sure there is extra security and to pass out fliers with a picture of the suspect.