Question: The 2170 mile Oregon Trail connected various towns along a 150 mile long valley, forms the cultural and political heart of Oregon, and is home to three of Oregon's largest cities, including which city that is the state capital?
Sentence (from "Willamette Valley"): The Willamette River flows the entire length of the valley, and it is surrounded by mountains on three sides – the Cascade Range to the east, the Oregon Coast Range to the west, and the Calapooya Mountains to the south.
Relevant evidence: No