Final answer:
The Grand Canyon is a major land feature formed through weathering and erosion by the Colorado River.
Step-by-step explanation:
The major land feature formed through weathering and erosion by the Colorado River is the Grand Canyon. Over millions of years, the Colorado River cut through rock layers, forming the canyon's deep and intricate landscapes. The Grand Canyon preserves an extensive geologic record with rocks ranging from 1,840 to 270 million years old, and its formation is tied to both the erosion from the Colorado River and significant tectonic events, including the Laramide orogeny that occurred 50 to 70 million years ago.