On July 3, 2013, about 1715 mountain daylight time, an experimental amateur built Boson, RV-4, N220CP, sustained substantial damage from a runway overrun during landing roll, at the General Dick Stout Field Airport (1L8) Hurricane, Utah. The airplane was registered to and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91. The private pilot was seriously injured. Visual meteorological conditions prevailed and no flight plan was filed for the personal flight which originated from Cedar City Regional Airport (CDC) Cedar City, Utah, about 1630, with a destination of 1L8. In a written statement to the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) the pilot reported that he did not recall the circumstances of the accident. Two witnesses located near the airport runway reported that the airplane landed long and then departed the runway surface at the end of runway 19. The airplane came to rest in a ravine about 100 yards from the departure end of the runway. One witness stated that the airplane's engine noise was normal and the airplane was moving at a high rate of speed upon landing. Examination of the accident site was conducted by a Federal Aviation Administration inspector, who was able to obtain flight control and engine continuity and reported no anomalies. The airplane's fuselage and wings sustained substantial damage. A review of recorded weather data from the CDC automated weather observation station revealed at 1653 conditions were wind 320 degrees at 8 knots. Postaccident examination of the airplane and engine was conducted by a certified airframe and powerplant mechanic, under the supervision of the NTSB IIC investigator-in-charge. Flight control continuity was established throughout all primary flight control surfaces from the cockpit controls. Braking continuity was established and the brakes and tires were unremarkable. An engine run was accomplished using an external fuel source that was connected directly to the carburetor fuel port. An external battery was used to start the engine. The engine functioned normally throughout a various range of power settings and no anomalies were noted. The examination of the airplane and engine revealed no evidence of mechanical anomalies or failures that would have precluded normal operation. For additional information, see the Airframe and Engine Examination Report in the Public docket.