At 1230 Mountain time, the airplane landed gear-up at the end of a Part 135 tour flight. The pilot and five passengers were not injured. The airplane sustained substantial damage to the undercarriage/fuselage after sliding 1300 feet down the runway. Visual conditions prevailed. The pilot selected 10 degrees of flaps, and then banked the airplane to show a point of interest to passengers. He later wrote, “This action so close to the runway distracted me, and I failed to lower the gear.”