03/06/1920 : Milwaukee Railroad's tug-of-war is held at Kent, Washington, between a steam locomotive & a electric locomotive. (the electric locomotive won)
10/01/1922 : The Northern Pacific Railway divides the Puget Sound Division into the Seattle & Tacoma Divisions.
04/01/1925 : Great Northern, Northern Pacific & the Union Pacific, pool their passenger service from Seattle, Washington to Portland, Oregon.
04/10/1925 : The Columbia & Cowlitz Railway is incorporated.
09/25/1925 : Great Northern Railway's engine # 2517 leaves Seattle, Washington on its famous Silk Train marathon.
10/03/1925 : Northern Pacific Railway begins operation from Stimson to Shelton, Washington. (15.3 miles)
11/26/1925 : Great Northern Railway Board of Directors authorizes construction of the new Cascade Tunnel.
12/28/1925 : Drilling begins at both ends of the new Cascade Tunnel.
03/18/1926 : Northern Pacific Railway engine # 1844 leaves Auburn, Washington on its record run to St. Paul, MN.
10/22/1926 : Great Northern Railway receives its first diesel locomotive.