Noxon Rapids: Clark Fork River, MT May 20, 2011November 12, 2011 Hydroelectric Projects, Montana Hydroelectric Project, NW Hydro and Tours
O.J. Power Company: Mill Creek, ID May 21, 2011May 24, 2011 Hydroelectric Projects, Idaho Hydroelectric Projects, NW Hydro and Tours
Oak Grove: Clackamas River Oak Grove Fork, OR May 16, 2011December 28, 2011 Hydroelectric Projects, NW Hydro and Tours, Oregon Hydroelectric Projects
Odell Creek: Odell Creek, OR May 16, 2011May 25, 2011 Hydroelectric Projects, NW Hydro and Tours, Oregon Hydroelectric Projects
Oneida: Bear River, ID May 21, 2011November 12, 2011 Hydroelectric Projects, Idaho Hydroelectric Projects, NW Hydro and Tours
Opal Springs: Crooked River, OR May 16, 2011May 25, 2011 Hydroelectric Projects, NW Hydro and Tours, Oregon Hydroelectric Projects
Orchard Avenue: Tieton River, WA February 9, 2011November 12, 2011 Hydroelectric Projects, NW Hydro and Tours, Washington Hydroelectric Projects
Oregon City: Willamette River, OR May 16, 2011May 25, 2011 Hydroelectric Projects, NW Hydro and Tours, Oregon Hydroelectric Projects
Owyhee Tunnel No. 1: Owyhee Lake, OR May 16, 2011May 25, 2011 Hydroelectric Projects, NW Hydro and Tours, Oregon Hydroelectric Projects
