Lost Lake in Oregon disappears each year, the water spiraling down a basin like bath water down a drain. Amazingly, scientists do not know where the water heads to as temperatures start to warm, although many believe an underground aquifer is the most probable destination for the water.

Water leaves the lake each year, traveling though an ancient lava tube. Normally, this water is replenished through the input of creeks. However, when these dry out due to rising temperatures, water leaving the lake through the natural tunnel is not replaced, and the lake's level drops.

As the lake drains, this massive amount of water pours into the six-foot-wide lava tube, draining the lake. For most of the year, however, the water level remains fairly steady as water coming in balances water lost down the drain and to evaporation. The cause of the mysterious loss of the lake each year has baffled scientists for centuries.

The lava tube was created long ago as magma moved underground, occasionally rising to the surface as lava. After the geology in the location cooled down, the tunnel became a path to ferry water out of the lake to parts unknown. Volcanic rock is often porous, which could allow the water to sit underground after leaving the lake bed. An aquifer in that region would likely feed springs on each side of the Cascade Mountains, supplying human populations with water.

"Eventually that same water pops up out and I'm having it in my morning coffee right now," Jude McHugh, a representative of the Willamette National Forest, said.

Some local residents have attempted to block the hole to prevent the lake from draining, but they have been unsuccessful. McHugh told the press that if such a plan were to succeed, it could cause the lake to overflow, possibly damaging a street near the waterway.

"If anyone was ever successful at plugging it — which we're not sure they could do — it would just result in the lake flooding, and the road; it's an important part of how the road was designed," McHugh said.

Fish Lake, not far from Lost Lake, also drains as temperatures rise, but water from Fish Lake absorbs slowly into the porous volcanic rock rather than traveling down a drain.  

The state of Oregon has 19 water bodies named Lost Lake.

Video of Lost Lake draining away like a bathtub is available on the Bend Bulletin YouTube channel.