There are several types of lift gliders can use, and one of the most fun is called orographic lift. This is when air is forced from a lower elevation to a higher one by terrain.
In the case of a ridge, wind from the windward side of the ridge will blow up the ridge and create lift just on the windward side of the ridge. Surface winds of 15-20 knots that are perpendicular to the ridge are ideal, but winds within 45° can provide adequate lift.
However, be aware that on the leeward side of the ridge, you will find a potentially dangerous amount of sink.
Accordingly, all turns should be made away from the ridge. Also, pass another glider on the ridge side, anticipating the other glider will turn away from the ridge.
If you want to have some real fun, contact Sarah at Chilhowee Gliderport about doing some ridge flying.
Mountain Wave Soaring
Another type of orographic lift is mountain wave. These waves form on the leeward side of the terrain, and can extend for many miles both up and out from the mountain. More or less normal people with moderately high performrance gliders routinely fly them up to 30,000 feet in wave. The Perlan 2 reached a record 52,000 feet in a wave off of Argentina.