On July 28, 2000, at 0540 hours Pacific daylight time, a Bell 47G-5 helicopter, N7885S, was substantially damaged by impact with high-tension electrical power transmission wires and subsequent impact with terrain, 1/4 mile west of King City, California. The commercial pilot was not injured. Instrument meteorological conditions prevailed and no flight plan was filed for the agricultural application flight, which was operated under 14 CFR Part 137 by Soilserv, Incorporated. The helicopter departed from the Mesa Del Rey airport, King City, at 0535 The pilot reported that he did not obtain a preflight weather briefing. He had taken off at dawn and was en route to the spraying location beneath a 300-foot solid overcast with 1/4 to 1/2-mile visibility. He flew into a fog bank and lost visual contact with the ground. He lowered the collective control and descended toward the ground to regain visual reference; however, the tail rotor contacted the power lines before he regained visual contact. He then lowered the collective further and reduced engine power to regain directional control and the aircraft impacted the ground in an upright attitude.