On August 16, 1998, at 1951 hours Pacific daylight time, a Piper PA-28-140, N291HA, sustained substantial damage when it veered off the left side of runway 18 while landing at the Henderson, Nevada, airport. The flight was conducted under the provisions of 14 CFR Part 91 by the owner/operator. The private pilot, the sole occupant, departed from Gillespie Field in San Diego, California, at 1750 for the personal flight to Henderson. Visual meteorological conditions prevailed and a VFR flight plan was filed. The pilot was not injured. A review of the recorded air-ground communications tapes from the Henderson air traffic control tower indicated the pilot was advised on his initial contact that winds were 190 degrees at 8 knots. The pilot asked the tower to repeat the winds and they complied. On final approach the pilot stated he noticed the aircraft was pushing to the left and tried correcting with right control yoke and left rudder. He had the second notch of flaps selected and power on. He said that in the flare he was startled and distracted by the stall light coming on. In his excitement he kept the throttle full in until he was off the runway. The aircraft encountered rocks and came to a stop. The pilot reported that the lighting conditions at the time of day, shortly after sundown, affected his visual acuity. A sun-moon computer program determined the sun was at -4.2 degrees on a magnetic bearing of 277.7 degrees. Sunset was at 1933; civil twilight began at 2001.