HWY 242 leading to the Dee Wright Observatory is CLOSED FOR THE SEASON. In the midst of a barren lava landscape discover this memorable monument. This historic observatory, built of lava rock, offers stunning panoramic views of Cascade Mountain peaks. There are interpretive panels, a half-mile (0.8 km) paved trail through lava flows, and a wheelchair accessible trail up into the observatory. Hwy 242 access to the Dee Wright Observatory typically closes to vehicles between November and June depending on snow conditions.