You're looking at the sternwheeler **_Portland_**, a historic steam-powered tugboat built in 1947, designed to operate in shallow waters on the Columbia and Willamette Rivers. It's the last active steam-powered sternwheel tug in the US, notable for its unique propulsion system where a large paddlewheel at the rear pushes the boat forward. This vessel is part of the Oregon Maritime Museum, docked on the Willamette River.