Drive Guide for an all-day tour of Lake Missoula Flood evidence in Clackamas County. Highlights of the trip include: a newly discovered spillway between the Clackamas Valley and the Willamette Valley. Baker Cabin where the Lake Missoula Flood created a short-lived waterfall and carved holes in the basalt which the Native Americans later used for grinding stones. A bird’s eye view of the Carver Gap and flood channel. The reputed second largest glacial erratic in Oregon. Canemah – a scabland on the east side of the Willamette River. Willamette Falls which is a receding waterfall created by the ice age floods.