On July 16, 2000, about 1045 hours mountain standard time, an Aeronca 7DC, N4462E, operated by Arizona Aviation, Mesa, Arizona, collided with a cactus during an attempted takeoff from an open field about 19 nautical miles southwest of Payson, Arizona. The airplane was substantially damaged. The commercial certificated pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed during the personal flight, and no flight plan was filed. The flight was performed under 14 CFR Part 91, and it was originating at the time of the mishap. The pilot reported to the National Transportation Safety Board investigator that on a previous date he had landed and taken off from the open field/clearing without difficulty. The clearing is surrounded, in part, by native vegetation. The pilot stated that during the ground roll of his attempted takeoff on the accident flight, the airplane collided with a cactus. Thereafter, he lost control of the airplane and it ground looped. The pilot also indicated that the airplane contacted the cactus because the available ground roll distance was inadequate. The dirt clearing was about 800 feet long by 50 feet wide. At the time, the wind was light and variable and the temperature was about 90 degrees Fahrenheit. The accident site elevation was about 2,380 feet mean sea level. The computed density altitude was between 4,800 and 5,000 feet. Additional information was received from the investigating park ranger, a responding police officer, the airplane's owner/operator, and the Federal Aviation Administration (FAA) coordinator. The federal park ranger stated the mishap occurred in the Mazatzal Wilderness Area of the Tonto National Forest, at an approximate location of north 34 degrees 12.2 minutes by west 111 degrees 41.8 minutes. The wilderness area is depicted on the Phoenix Sectional Area Aeronautical Chart. The park ranger additionally reported that the pilot did not have the government's permission to utilize the clearing for the operation of the airplane. The airplane's owner/operator stated that the pilot did not have permission to land the rented airplane on uncharted, unpaved airstrips or clearings.