Wanderlust World Wanderlust World No. The Grand Canyon was carved by the Colorado River, not glaciers.
| Feature | Glacial Trough (U-Valley) | River Canyon (V-Valley) |
|---|---|---|
| Cross-section | U-shaped: wide, flat bottom, steep straight walls | V-shaped: narrow bottom, sloping walls |
| Agent | Glacier (ice plucking, abrasion) | River (hydraulic action, abrasion, corrosion) |
| Typical setting | High mountains, formerly glaciated regions | Anywhere with flowing water & relief |
| Grand Canyon? | No glaciers in its history at this latitude/elevation | Yes—Colorado River, 5-6 Myr incision |
The Grand Canyon is the textbook river canyon—Earth's most spectacular exposure of layered time, cut by water, not ice.