Construction began less than a year later, jumping off from both ends and some in-between points in April, 1906. The route chosen, then estimated to cost $60 million, was to be 150 miles shorter than the combined NP/Burlington route and 80 miles shorter than the GN/ Burlington route. The Milwaukee’s route also was chosen so as to have better grades than the competitive routes. However, it also was an expensive route since the Milwaukee—given no land grants—had to purchase land or buy smaller railroads to make the extension.
In a remarkable engineering feat, about 2,300 miles of railroad—built on a path going through five major mountain ranges, the Saddles, Belts, Rockies, Cascades and Bitter Roots—was built in only three years.
After construction started in 1906, the line was open for westward traffic to Harlowton, Mont., by April of 1908, and then was open for full passenger service over the entire route to Seattle by August, 1909.
On May 28, 1911, the Milwaukee began operating its Columbian and Olympian passenger trains between Chicago and the Northwest.
During the four years from 1906 through 1910, the Milwaukee Road grew from 7,000 to nearly 10,000 route miles, because of the extension and because of the branch feeder lines that either were built or acquired.
The Pacific Extension
An entry from Four Generations on the Line
"The Trail of the Olympian"