The pilot initiated the accident flight from the Bozeman Airport. After departure, the pilot flew to his intended Ennis Lake destination, and he proceeded to land. The pilot made a normal approach and touchdown on the lake in his amphibious, experimental seaplane. The seaplane nosed over when the landing gear wheels came in contact with the water. The forward portion of the seaplane's fuselage was crushed, and the pilot was seriously injured. The pilot subsequently reported that during the accident flight he had not experienced any mechanical malfunction with his airplane, and he "had forgotten to retract the landing gear" prior to the water landing.