A Bell Helicopter 206 was stolen from the operator during an on-demand air taxi flight. A passenger was first transported between two airports. The passenger then asked the pilot to fly by a mine site. The helicopter landed at the mine site and was greeted by an individual carrying a rifle. The pilot was assaulted and knocked unconscious. The helicopter was then flown away. The helicopter was found three days later by police abandoned on uneven desert terrain. The wreckage was described as 'rolled up in a ball.' Traces of blood and hair were found in the helicopter's overhead structure above the pilot's seat. Samples of the blood and hair did not match those of the assailed pilot. The helicopter had rolled over during a landing attempt. The time and date of the accident cannot be determined. The identity of the pilot cannot be determined. The theft of the helicopter is being investigated by law enforcement agencies.