While driving home my sister and I witnessed a streak of light travel across the horizon and dissapear.My sister and I reached the bottom of the valley right before Whitetail and I was looking ahead at the road when a FAST streak of white/gray light went through the middle of my windsheild moving west to east, it was horizontal with the horizon so it couldn't of been a shooting star and it was so fast and thin that it couldn't of been a aircraft. My sister and I were so stunned we didn't think to look at it as it left to go east but after a few seconds we looked to the east and it had dissapeared.