The Ruddy Collins House is believed to be the oldest house still standing in Whitman County, and one of the oldest buildings in southeastern Washington, built in 1870–71. It is located just inside the Washington state line at the head of Hatwai Canyon, a natural cleavage that knifes for several miles down to the Clearwater River near its junction with the Snake River at the twin cities of Lewiston, Idaho, and Clarkston, Washington. Although one or two other permanent settlers had preceded him in the area, Michael Ruddy arrived in the fall of 1870. The great influx of population, made up to a large extent of German Catholic immigrants, did not begin until the middle of the 1870s.