Pine Mountain in central Oregon, east of Bend and south of U.S. Route 20, is a rhyolitic mountain known for Pine Mountain Observatory and for smooth “glass off” weather that attracts paragliders. Geologically, it belongs to the Deschutes Formation associated with Cascade volcanism and marks that formation’s southeasternmost exposure, with an age similar to nearby Cline Buttes. The mountain shows heavy erosion and thick soils, with basalt, rhyolite, andesite, and dacite, while pumiceous dust and lapilli dunes line its northwest flank. Its scientific role and unusual flying conditions give this modest high desert mountain significance beyond its size.