The U.S. Army Corps of Engineers has restricted boat access at the The Dalles Dam downstream navigation approach channel to lock users only.  The Dalles Lock and Dam operations manager Ron Twiner says the restriction was necessary to ensure public safety due to the river current and the lock’s proximity to the dam.  Its purpose is to keep as much distance as possible between river traffic and small boats near the lock’s approach, which is a constrained area.  In addition to the danger of collision, large vessels can displace water and currents can rapidly change as the navigation lock cycles water through the structure, causing another potentially dangerous condition.