What time was it? (skylab wouldn't be visible before sunset...)
Sky conditions: Cloudy or clear? What were the positions of sun and moon at that time? (Were you seeing a reflection?)
Did the bright spot move? How long was it visible?
If you could see Cherry mountain and guess at some more distant peaks, there must have been a fair amount of ambient light. The first thing to come to mind that's bright enough to be visible before nightfall is Venus. Jupiter and Saturn are possibilities too. A manmade airborne light source (airplane most likely) would certainly be bright enough, but would eventually appear to move (could take a while if it was headed straight towards you). A very reflective balloon is also possible. Can't rule out a ground-based light, but it seems a little unlikely - it would have to be very big and bright (probably very far) and somebody would have to have a good reason to haul it up a mountain.