...the first Oregon railroad, the six-mile-long portage line near what is now the town of Cascade Locks, opened in 1855. The car, on wooden tracks, carried both goods and people and was drawn by mule.
A serious barrier to quantity freight transportation during the era when mining booms in Idaho and eastern Oregon made steamboat transportation on the Columbia a huge business, the Cascades were again mastered, this time at water level by a wooden railed portage tramway over which mule drawn cars, laden with merchandise, rattled from one waiting steamer to another. This proved so profitable a venture that steel rails replaced the wooden ones, and the Oregon Pony, first steel locomotive to operate in Oregon and now on exhibition at the Union Station grounds in Portland, was imported to draw the cars.