The Crater Lake Monster

In Crater Lake, Northern California, Dr. Richard Calkins is informed by his colleague Dan Turner that he and his girlfriend Susan Patterson have made an incredible discovery in a nearby cave system. The three head down and discover a system of cave drawings, including what appears to be a depiction of people fighting off a Plesiosaurus, thus providing evidence that dinosaurs existed at the same time as humans did. However, a flaming meteorite crashes into the lake just overhead, resulting in a cave-in that destroys the cave system and the drawings, while the three scientists are barely able to escape alive. The local sheriff, Steve Hanson, sees the meteorite crash and radios in the incident before continuing on his patrol.