The major uplift of the Rocky Mountains occurred during the Laramide Orogeny, which peaked around 70 million years ago.

The Rocky Mountains are relatively young compared to some other mountain ranges. Their primary formation occurred during the Laramide Orogeny, a period of mountain building that took place roughly 80 to 55 million years ago. The peak of this activity, when the most significant uplift occurred, was around 70 million years ago. While some earlier geological activity contributed to the region's base, it was the Laramide Orogeny that gave the Rockies their current form.