The student pilot and his instructor were returning to their home airport after night cross-country instructional fight. As they descended toward the airport, the airplanes wheels contacted terrain on a ridge about nine miles from the planned destination, and about 1650 feet higher than the airport elevation. Although the airplane initially rolled across the terrain at a high rate of speed, it soon contacted a road, resulting in loss of control and further contact with the terrain. There was substantial damage to the airplanes fuselage. Although the sky was clear with no restrictions to visibility, it was a dark night with no moonlight, and neither pilot saw the terrain prior to the accident. Injuries were unknown.