Northwest has 4 regions with 3, 2, 4, 3 stations each.
See combined Topo Map.
Region 1: Helena, Idaho Falls, Boise
46.58, -112.01 Helena 43.5, -112.01 Idaho Falls 43.63, -116.2 Boise
Region 2: Rock Springs, Salt Lake City
41.58, -109.22 Rock Springs 40.75, -111.86 Salt Lake City
Region 3: Spokane, Walla Walla, Seattle, Tacoma
47.65, -117.41 Spokane 46.05, -118.33 Walla Walla 47.6, -122.33 Seattle 47.23, -122.45 Tacoma
Region 4: Bend, Eugene, Portland Or
44.06, -121.28 Bend 44.03, -123.1 Eugene 45.51, -123.68 Portland Or