Malheur Cave
| Malheur Cave | |
|---|---|
| Malheur Cave Lake | |
Interactive map of Malheur Cave | |
| Location | Harney County, Oregon, U.S. |
| Coordinates | 43°22′37″N 118°17′30″W / 43.3769°N 118.2917°W |
| Length | 3,000 feet (910 m) |
| Geology | Lava tube |
| Entrances | 1 |
| Hazards | Seasonal flooding, uneven terrain |
| Access | Private (Robert Burns Lodge No. 97) |
| Features | Underground lake, stadium-style seating, Masonic altar |
Malheur Cave is a lava tube cave located in Harney County, Oregon, approximately 17 miles (27 km) east of Crane Hot Springs and 52 miles (84 km) east of Burns, Oregon. The cave is privately owned by the Robert Burns Masonic Lodge No. 97 and is notable for functioning as an underground meeting hall for Freemasonry since 1938.
The cave contains an underground lake at its lower end; the United States Geological Survey (USGS) monitors the water level under the designation "Malheur Cave Lake." While historically open to visitors, the cave was closed to the general public in 2019 due to vandalism. It has subsequently become a subject of internet urban legends and conspiracy theories.