The United States Pacific Railroad surveyors explored multiple routes to the Pacific Ocean. Isaac Stevens concluded that there were at least two preferable routes. The easiest, but longer route was south to Walla Walla and then west along the north side of the Columbia River to Portland. The other was over the Cascade Mountains at Snoqualmie Pass. While shorter, this Cascade route presented several engineering challenges. The railroad would need to dig a tunnel near the summit or add steam engines to power the cars up the last few miles over the pass.

Stevens’ survey report was dismissed by his boss, Secretary of War Jefferson Davis, as impractical and too costly. Recent research, however, suggests that Davis, who later led the Confederacy during the Civil War, had already committed to a Southern route.

The Northern Pacific transcontinental railroad was completed in September 1883 along the Columbia River route. From there it headed north to the newly designated terminus in Tacoma. A more direct route over Stampede Pass was up and running in 1888. Stevens would not live to see any of this. He was killed in the Civil War at Chantilly in 1862.

There would be many more surveys after Stevens’. But his is remembered for more than its engineering accomplishments. At the time, the Northern Plains were thought to be of little value, part of the "Great American Desert." Stevens helped to counter public perceptions that the North was a wasteland and that its mountains were impassable.1