Before the concrete Chicago, Milwaukee and St. Paul Viaduct was built in 1915, this timber trestle was what the trains used. The "new" bridge now serves as a portion of the Milwaukee Road Trail and is one of the main attractions of the hike or bike ride. The bridge also overlooks Tohotonimme (or Steptoe) Battlefield, where one of the region's last wars between Tribal forces and US Cavalrymen.

Image courtesy of Whitman County Rural Heritage.
http://www.washingtonruralheritage.org/cdm/singleitem/collection/whitman/id/1298/rec/53