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Three Sisters

From Oregon Hikers Field Guide

View of the Three Sisters from nearby Mount Scott (cfm)

The Three Sisters are the dominant mountains in the Cascades south of Mount Jefferson and east of Eugene. They are an ever-present feature of the skyline from the city of Bend.


Volcanic History

The Three Sisters area has a long, complicated eruptive history. North Sister, the oldest of the trio, has been inactive for over 100,000 years. Middle Sister was last active 10—12,000 years ago. While the main cone at South Sister is probably 25,000 years old, the most recent activity may be as little as 2,000 years old. A bulge in the terrain three miles west of South Sister grew about half an inch a year from the mid-1990s but had almost halted growing by 2015.

Climbing Information

North Sister is a difficult summit, only reachable by people with the appropriate climbing equipment and experience.

Middle Sister is a fairly routine but long scramble in good weather. Probably the the most common route is via the Hayden Glacier on the east side to the north ridge and then to the summit.

The summit of South Sister on the other hand, is reachable by a normal hiking trail. You'll need a lot of stamina and water, but no special equipment. The hike begins at the Devils Lake Trailhead and climbs 4900 feet in 5.5 miles to the summit.

Hiking notes

The Three Sisters lie in the middle of the appropriately named Three Sisters Wilderness. All visitors in the area must fill out a free wilderness permit. All motorized vehicles or tools are prohibited.



Oregon Hikers Field Guide is built as a collaborative effort by its user community. While we make every effort to fact-check, information found here should be considered anecdotal. You should cross-check against other references before planning a hike. Trail routing and conditions are subject to change. Please contact us if you notice errors on this page.

Hiking is a potentially risky activity, and the entire risk for users of this field guide is assumed by the user, and in no event shall Trailkeepers of Oregon be liable for any injury or damages suffered as a result of relying on content in this field guide. All content posted on the field guide becomes the property of Trailkeepers of Oregon, and may not be used without permission.