On September 13, 2021, at 1830 mountain daylight time, a Kolb Mark III airplane, N4365E, was substantially damaged when it was involved in an accident near Steamboat Springs, Colorado. The pilot sustained serious injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot’s wife, who witnessed the accident, reported that the pilot recently purchased the airplane. She stated that the pilot flew the airplane with the previous owner in Indiana before driving it on a trailer to Steamboat Springs. On the day of the accident, the pilot intended to taxi the airplane around his private airstrip to get used to the feel of the airplane. The airplane subsequently lifted off, cleared several fences, but only made it about 20 ft above the ground when the airplane’s nose suddenly lowered and impacted the ground. The airplane sustained substantial damage to the fuselage. The witness stated the engine was still running and she was unable to turn it off when she reached the accident site. The pilot told the witness that he did not command the airplane down but that it just fell. The pilot later told a family member that he stalled the airplane. The airplane was not made available for investigators to examine the airframe or flight control system. The pilot did not submit the National Transportation Safety Board Pilot/Operator Aircraft Accident/Incident Report (NTSB Form 6120.1).