Flashing Light Sighting 5/9/11 in Nice (Lake County) CASighting was in Lake County California, driving north on Hiway 29 from Lakeport to Nice (pronounced niece), and continued as we turned onto Hiway 20 heading east.I was driving north on 29 with my son and his girlfriend riding in the vehicle, as well. We all noticed the lights about the same time as we drove up onto the hiway from 11th street in Lakeport. At first we thought it was lightening strikes but I realized that the flashes were not from the sky to the ground but in fact were coming from the ground and shining into the sky.As we drove north along Hiway 29, it actually goes up hill somewhat, so as we gained altitude we could see that the lights were actually coming from behind the foothills, behind the town of Nice along Hiway 20.The lights did not seem to flash with any regularity or pattern but seemed to be very random and the intensity would shift, as if the direction of the craft emitting them was changing angles or manipulating the lights in some sort of search pattern. There are no roads along the ridge that the lights were traveling; this area is far to steep and jagged for any wheeled vehicles to have traversed so easily and as quickly as we saw the lights moving.The lights continued as we arrived at home in Nice. At this point we got out of the vehicle and walked to the front of our property and we saw the lights flash several times more. We wanted to see them but we also were attempting to listen for any noises, like a possible rotary blade "whooping" sound, you would expect to hear from helicopters. We saw the lights but heard nothing.My son spoke with some of his friends the next day and several others from Lakeport to Upper Lake to Nice, all saw the lights but heard no noise. This is a very rural area with only small towns (the entire county of Lake has just over 62,000 population) and the entire northern area of the county is like a big bowl, so sounds and noise travel easily over a great distances. If these light emitting UFOs were making noise at all we would have heard it.