COGS is a Central Oregon-based non-profit organization promoting a greater awareness and understanding of the geological sciences through technical presentations, educational outreach to schools, and field trips

Presentations resume in September

2021 Field Trips

COGS Field Trip: Fault Scarps of Mt. Hood (south side)

June 27, 2021, 9 am-5 pm

Led by Ian Madin, Senior Scientist, Earthquake Hazard Geologist - Oregon Department of Geology and Mineral Industries.

This field trip will visit several surface expressions of faulting on the south side of Mt. Hood which have also been identified on lidar imagery. This trip is a great opportunity to see how traditional surface geology techniques can be integrated with quantitative methods based on imagery. There will be a total of three or four stops. Total distance walked will be minimal but there may be some uneven terrain and downed trees to navigate around. This trip is a subset of a two day trip and the field trip guide is available at::  (pages 100-109)

This trip is limited to 12 participants. As a reminder, all participants are required to be fully vaccianted and must be a COGS member or a guest of one. Ride sharing is voluntary but is encouraged due to limited parking at some of the field stops. Anticipating high demand and to give everyone a fair chance, attendance will be determined by a lottery. If interested in registering, please email . Groups should include all the names in the party. Prospective participants will be notified of their status on June 18.

COGS Geo-Exploration Meetup

COGS is pleased to announce the formation of a COGS Meetup group to offer COGS members a variety of informal events including geo-explorations, hikes and bike rides to geologically interesting sites, lunch-and-learn events, and online chats. In order to join the COGS Meetup, you can either search "Central Oregon Geosciences Society Meetup" or go to the following link:

On the COGS Meetup site, you will find a red button stating "join this group". Once you have joined the group, you will start receiving notices of COGS Meetup events.


Geoscience Events & Activities by Others


Friday June 11th Zoom Lecture

Dr. Emily Cahoon

Sunstone Clues to Flood Basalt Magmatism

Dr. Emily Cahoon will be discussing her research connecting our state's official gemstone, the Oregon Sunstone, with the vast outpouring of basaltic lava covering much of the Pacific Northwest, the Columbia River Basalt Group (CRBG). These lavas were sourced from the Yellowstone plume and erupted through fissures across eastern Washington and Oregon approximately 17 million years ago.