Within a year, and despite legal challenges from Harriman, who wished to block its construction, the line had been built as far as Pasco, Washington, along the Columbia River, where there was a connection with Northern Pacific lines. The first section to open was from Pasco west through Wishram to cliffs (near Maryhill), a length of , on December 15, 1907. Operation was extended west to Lyle, for a total of , on January 15, 1908, as construction continued on the section from there to Vancouver.