U.S. States with the Most Valleys: Mountainous Regions from Colorado to New Hampshire

Valleys form where tectonics, erosion, and glaciation carve lowlands between highlands. States with extensive mountain ranges have the most valleys:

1. Colorado — Rockies: Cache la Poudre, San Luis, Yampa, Roaring Fork valleys.
2. California — Sierra Nevada, Coast Ranges: Yosemite, Napa, Sonoma, Central, Imperial, Death Valley.
3. Washington — Cascades, Olympics: Methow, Skagit, Yakima, Hoh valleys.
4. Oregon — Cascades, Siskiyous: Willamette, Rogue, Umpqua, Grande Ronde valleys.
5. Idaho — Rockies, Sawtooths: Sawtooth, Salmon River, Wood River, Treasure Valley.
6. West Virginia — Appalachians: New River Gorge, Shenandoah (extends to VA), Greenbrier, Potomac valleys.
7. Pennsylvania — Appalachians: Wyoming, Lehigh, Cumberland, Susquehanna valleys.
8. New York — Adirondacks, Catskills: Hudson, Mohawk, Finger Lakes (glacial valleys), Schoharie valleys.
9. Vermont — Green Mountains: Champlain, Mad River, Winooski, Connecticut River valleys.
10. New Hampshire — White Mountains: Pemigewasset, Conway, Connecticut River, Lost River valleys.

Other valley-rich states: Montana, Wyoming, Utah, Arizona, Nevada, North Carolina, Tennessee, Kentucky, Virginia, Maryland.