premise: The Columbia River has boats.
hypothesis: Columbia River . In the late 18th century , a private American ship became the first non-indigenous vessel to enter the river ; it was followed by a British explorer , who navigated past the Oregon Coast Range into the Willamette Valley . Steamships along the river linked communities and facilitated trade ; the arrival of railroads in the late 19th century , many running along the river , supplemented these links . To aid ship and barge navigation , locks have been built along the lower Columbia and its tributaries , and dredging has opened , maintained , and enlarged shipping channels .