USGS Photograph by Lyn Topinka
Geology of Mount Bachelor and the Three Sisters Area
July 14, 10 AM - 4 PM
Trip Leader: Daniele McKay
The central Oregon Cascades have been shaped by geologically recent volcanism from hundreds of individual vents located in a relatively small area. Activity in this region has produced both mafic and silicic lava flows, tephra deposits, and examples of nearly every type of volcanic landform on Earth.
On this field trip we will explore recent volcanism in the central Oregon Cascades from the spectacular viewpoint of Pine Marten Lodge at Mount Bachelor. We will meet in the West Village parking lot and take the summer chairlift to Pine Marten Lodge, where we will talk about the past (and possibly future) eruptive history of Mount Bachelor and the Three Sisters.
See the Mt. Bachelor ski resort website for scenic lift ride prices:
Summer Activities - Scenic Chairlift Ride
Scenic lift tickets can be purchased in advance or on the day of the field trip. Alternatively, participants can hike on their own to Pine Marten Lodge and meet the group between 10:30 and 11:00 on the north deck of the lodge.
See the Mt. Bachelor ski resort website for trail information:
Summer Activities - Summer Hiking Trails
Field Trip Overview:
The group will meet at 10:00 am in the Mount Bachelor West Village parking lot for an introduction and overview of the day. We will then take the summer lift to Pine Marten Lodge and plan to arrive at the lodge between 10:30 and 11:00. From there we will discuss regional volcanic activity from the deck of the lodge, with spectacular views of the Three Sisters, Broken Top, and other volcanic features.
We will eat lunch at the lodge, followed by further discussions and an optional walk to nearby rock outcrops. At about 2:00 we will take the lift back down to the West Village parking lot, followed by an optional walk to tephra deposits near the Mount Bachelor Nordic Center.
This field trip is geared toward a general audience who wants to learn more about the volcanic history of the central Oregon Cascades. No geologic background is necessary.
Bring a packed lunch to eat at the lodge, or purchase lunch in the lodge at Scapolo's Bistro. Also bring a water bottle (can be refilled in the lodge), sunscreen, and clothing for the day. Pine Marten Lodge is located at 7,700 feet elevation and can be windy and chilly even when temperatures are warm in Bend.
Walking distances for the optional portions of the field trip will be less than a mile total, on generally flat but rocky terrain. This does not include the optional hike to Pine Marten Lodge, which is on well-maintained trails but entails about 1,300 feet elevation gain.
Participants interested in ride sharing should meet at the 'Signs' pull out on Century Drive just to the SW of the Mt. Washington/Reed Market Rd - Century Drive roundabout at 9:20 AM. This is an informal ride share and will be self-organizing.
Please note that although this event has no participation limit, registration is required and must be done via the registration button on the trip listing on the COGS website. Successful registration will be confirmed on the webpage by a light green box indicating registration was successful and by a confirmation email. If you do not get this email, you should try the registration process again.
