Adventure Oregon - Every spring, Lost Lake mysteriously drains into a giant hole that is likely a lava tube. Where the water goes, nobody knows. Fun location for a day or overnight trip about 75 miles east of Salem Oregon. To get to Lost Lake take Hwy 22 east from Salem to Hwy 20. Continue east on Hwy 20. Just NE of the Potato Hill Snow Park turn left on unmarked road to Lost Lake. The Lost Lake drain hole is not far from the day-use parking area.