An investigation is under way into a break-in at Bent's Old Fort National Historic Site in Colorado in which thieves took nine replica firearms and made off with an unknown amount of money.

Officials say three locks were broken by the thieves to give them access to the fort’s donation box, the Trade Room, and the fee collection area of the fort. Alarms and a quick response by Otero County Sheriff’s Office Deputies likely prevented further losses, park officials said.

The estimated value of the firearms taken in the robbery Tuesday is $9,000.

Burglaries also occurred in the past week at the Boggsville Historic Site south of Las Animas. Buffalo hides and cash were stolen there, park officials said.

A tip-line has been set up with the Otero County Sheriff's Office and a reward is being offered for any information that leads to the successful prosecution of this crime. Anyone with information about this case is urged to call the Sheriff’s Office at (719) 384-5941.