The Guymon Fire Department responded to a fire at Caktus Jack's Steakhouse, 2101 N US Highway 64, at 7:30 Saturday morning. According to Fire Chief, Grant Wadley, upon arrival, they discovered smoke rising from the back of the building. Wadley stated that, after gaining entry, firefighters found that the fire was primarily in the office area. A total of 5 fire department units with 21 firefighters responded to the scene. The back of the restaurant suffered severe fire damage with the rest of the building receiving heavy smoke and heat damage. Wadley estimated the dollar amount of the damage to be in the hundreds of thousands of dollars. The cause of the fire hasn't been determined at this time.