 In 1887, the Northern Pacific Railroad reached the town of Thorp, when the railroad’s management built a sidetrack out one mile west of the current town site and named it after the intrepid pioneer F. M. Thorp and his family.It took two years to build the Northern Pacific line from Old Town, now Union Gap, to Thorp.Chinese laborers or "coolies" were brought in first to build the Northern Pacific spur, and again to extend the Milwaukee Road through the Kittitas Valley.