Subscribe | UPI Odd Newsletter Subscribe SPRINGFIELD, Ore., May 6 (UPI) -- Officials with Oregon's Willamette National Forest said a collapsed lava tube is to blame for the aptly-named Lost Lake's annual disappearance. Jude McHugh, a spokeswoman for the Willamette National Forest, said a lava tube -- a tunnel-like structure created to drain lava during a volcanic eruption -- collapsed under Lost Lake, causing the body of water to drain and become a meadow after each winter. Advertisement "In Lost Lake, this particular lava tube collapsed and became the drain hole for that lake," McHugh told ABC News. The Bend Bulletin created a YouTube video showing the process of the lake's annual draining. Officials said the lake is constantly draining through the 6-foot-wide hole, but the phenomenon is more apparent during drier months, when the lake is not being filled by precipitation. Read More Florida woman uses Pizza Hut app to request 911 assistance Irish 3-year-old's snooker skills make him a viral star Massive Mexican flag sweeps soldier 45 feet into the air