Complex sentence: Other major dams in the Willamette watershed are owned by other interests, notably the hydroelectric facilities on the Clackamas River owned by Portland General Electric, such as the historic River Mill Hydroelectric Project, the Oak Grove, and the dam at Timothy Lake.
Split into simpler sentences: Other major dams in the Willamette watershed are owned by other interests; for example, several hydroelectric facilities on the Clackamas River are owned by Portland General Electric. They include the River Mill Hydroelectric Project, the Oak Grove project, and the dam at Timothy Lake.