On Sept. 24, 1853, a party of surveyors traversed up the eastern slope of the Rocky Mountains. They had left St. Paul, Minnesota in May, seeking the best route for a northern transcontinental railroad. As they lumbered up a narrow path, they admired the fall colors and other "beauties of nature." When the group reached the summit at Cadottes Pass at 4 p.m., Mother Nature showed her true colors. With little warning, a driving rain - mixed with hail, thunder and lightening - quickly soaked the party. Undaunted, the group’s leader, Isaac I. Stevens, "cordially and heartedly" welcomed his men to Washington Territory.1

This account of the ascent up the mountains, tells a larger story about railroad surveys and construction. The first few months of the trek went relatively smoothly. Surveying a railroad across flat, open prairie through what are now North Dakota and Montana was a straightforward proposition. Mountains, on the other hand, presented much "higher" challenges.

With a paltry $40,000 appropriation from Congress, the survey party consisted of 120 surveyors, scientists and military escorts. In addition to cataloging the terrain, the survey collected animals and plants for scientific research.

The mountains demanded the most attention. There were three ranges in total, the Rockies, the Bitterroots and the Cascades. They had been crossed many times since the days before Lewis and Clark. Native American and non-native beaver trappers and hunters were intimately familiar with the many passes. But there was little reliable recorded information on the terrain and the grade or steepness. No one had charted snow depth, temperature, rainfall and soil quality. Stevens estimated it would take years to compile that kind of data.