Constructing a bridge over a river is never simple. In 1876 the people who designed the Russian River bridge did not have computer models to rely on. They had to engineer a railroad bridge made primarily of wood that crossed a 200 foot stretch over a river famous for flooding in winter. The San Francisco and North Pacific Railroad didn't want to invest a lot of money in the bridge. The train was to haul lumber out of the Russian River gorge and it was obvious that once all the trees were cut down there would no longer be a need to carry lumber.