On October 25, 2007, about 1035 Pacific daylight time, a Bell 206L-1, N412KK, collided with trees and rolled over following a loss of control while maneuvering near Ramona, California. Blackhawk Helicopters, Inc., was operating the helicopter under the provisions of 14 CFR Part 91 during the aerial observation flight. The commercial pilot and three passengers were not injured; the helicopter sustained substantial damage. The local flight departed Ramona Airport, Ramona, about 1000. Visual meteorological conditions prevailed, and a company flight plan had been filed. In a written report to the National Transportation Safety Board, the pilot stated the flight was conducted to assess fire damage to utility assets from a recent fire in San Diego County. The operation required slow flight at low altitudes with many turns and course reversals. The pilot further stated, while rolling out of a turn at 100 feet agl, he noticed a reduction in airspeed. He applied forward cyclic and raised the collective in attempt to reach the desired airspeed and altitude. He noted feeling resistance to the forward cyclic movement. The helicopter responded by positioning into a nose high attitude. The pilot stated that a high power setting was needed to maintain altitude. The helicopter started to yaw to the right, which the pilot opined was due to the onset of loss of tail rotor effectiveness (LTE). He reduced power to counteract the LTE and the helicopter started to descend. The pilot decided to execute a precautionary landing. During the landing, the helicopter impacted trees and came to rest on it's left side. An FAA inspector responded to the accident site and examined the wreckage. He noted no mechanical anomalies with the helicopter.