Britannica
Sources used in this answer
How old are the Klamath Mountains compared with other Pacific coastal mountains?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
Pacific mountain system
Coast Mountains along the Torres Channel, an arm of Atlin Lake, northwestern British Columbia, Canada.
The Klamath Mountains are the oldest of the Pacific coastal mountains, with origins dating back to the early Paleozoic Era, approximately 500 million years ago.1
In contrast, other segments of the Pacific mountain system are significantly younger. For example, the Middle Cascade Range consists of volcanic materials from the Cenozoic Era, which encompasses only the past 65 million years. The complex geological history of the Klamath Mountains also involved tectonic plate collisions during the early Triassic Period (about 250 million to 245 million years ago), followed by intrusions of granite batholiths.1