Field Trips

COGS offers a variety of field trips led by experts on Oregon's geology.


Geo-Explorations

Informal hikes, bike rides, and other explorations of geologically interesting sites.


To participate in field trips and geo-explorations:

  • You must be a member of COGS, or a guest of a member, to participate in field trips and geo-explorations.
  • You must sign the COGS field trip and geo-exploration waiver.
  • Please arrive at the meeting location 5-10 minutes early to get signed in.
  • Check the weather report and plan accordingly. Remember that weather conditions can change quickly in central Oregon! Dress in layers and wear sturdy hiking shoes.
  • Bring plenty of water and snacks, pack a lunch if specified in the field trip description.
  • Please leave your pets at home – dogs are not allowed on COGS field trips. 

    COGS Field Trip & Geo-Exploration Waiver


    Upcoming Field Trips

      • 26 Apr 2025
      • 9:00 AM - 4:00 PM
      • Madras, OR
      • 8
      Register


      David Sherrod


      Willow Creek Field Trip

      Madras, OR

      Saturday, April 26

      9:00 AM - 4:00 PM


      Please join David Sherrod for a field trip focusing on the Deschutes Formation.

      The Deschutes Formation of central Oregon received its sediment and volcanic input chiefly from the west, the basin’s arc-adjacent alluvial plain. This COGS late April trip visits a part of the eastern side, the (relatively) inactive margin. Our journey begins with two road stops east of the town of Madras and third on the bluff overlooking Willow Creek. Those stops serve as introductions to the eastern edge of the Deschutes Formation and inactive-margin strata that will be examined in greater detail by hiking on the Willow Creek trail west of Madras. The trail traces the early 20th century railroad grade of the Oregon Trunk Railway. The walking part of the trip is 2.6 miles plus return (so 5 miles or so) with minimal elevation gain.

      Assemble at 8:30 AM at Madras’s Sahalee Park, near downtown Madras. There is a restroom available there.  A location to meet for ride sharing or caravaning from Bend will be arranged.  A meetup location in Redmond may be added if there is interest.  Please contact Derek Loeb at DerekLoeb@gmail.com with questions? 

      David Sherrod is a retired USGS geologist who has worked widely along the Oregon Cascade Range and its eastern flank.  He is the lead author of the Geologic Map of the Bend Quadrangle.  These days he self describes himself as foolishly pursuing geology as a hobby, including an ongoing project that will lead to a geologic map of the Madras 30- by 60-minute quadrangle.

      Please note that this event is limited to 12 participants and registration 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 don't get this email you should try the registration process again.






      • 27 Apr 2025
      • 9:00 AM - 4:00 PM
      • Madras, OR
      • 0
      Join waitlist


      David Sherrod


      Willow Creek Field Trip - Second Session

      Madras, OR

      Sunday, April 27

      9:00 AM - 4:00 PM


      Please join David Sherrod for a field trip focusing on the Deschutes Formation.

      The Deschutes Formation of central Oregon received its sediment and volcanic input chiefly from the west, the basin’s arc-adjacent alluvial plain. This COGS late April trip visits a part of the eastern side, the (relatively) inactive margin. Our journey begins with two road stops east of the town of Madras and third on the bluff overlooking Willow Creek. Those stops serve as introductions to the eastern edge of the Deschutes Formation and inactive-margin strata that will be examined in greater detail by hiking on the Willow Creek trail west of Madras. The trail traces the early 20th century railroad grade of the Oregon Trunk Railway. The walking part of the trip is 2.6 miles plus return (so 5 miles or so) with minimal elevation gain.

      Assemble at 8:30 AM at Madras’s Sahalee Park, near downtown Madras. There is a restroom available there.  A location to meet for ride sharing or caravaning from Bend will be arranged.  A meetup location in Redmond may be added if there is interest.  Please contact Derek Loeb at DerekLoeb@gmail.com with questions? 

      David Sherrod is a retired USGS geologist who has worked widely along the Oregon Cascade Range and its eastern flank.  He is the lead author of the Geologic Map of the Bend Quadrangle.  These days he self describes himself as foolishly pursuing geology as a hobby, including an ongoing project that will lead to a geologic map of the Madras 30- by 60-minute quadrangle.

      Please note that this event is limited to 12 participants and registration 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 don't get this email you should try the registration process again.






    Past Field Trips

    12 Apr 2025 Barnes Butte Geo-Exploration
    29 Mar 2025 Hollywood Road Geo-Exploration, Second Session Reschedule
    22 Mar 2025 Hollywood Road Geo-Exploration
    18 Oct 2024 Geo-Exploration: Head of the Metolius & Mile 29 Debris Flow
    13 Sep 2024 Alder Springs Geo-Exploration
    1 Sep 2024 Citizen science opportunity - basaltic andesite sample collection
    14 Jul 2024 Geology of Mount Bachelor and the Three Sisters Area
    7 Jul 2024 Three Fingered Jack Field Trip
    5 Jun 2024 Wildcat Caldera Field Trip
    19 Mar 2024 Second Session Added: Hydromagmatic Pinnacles of the Steelhead Falls Area Geo-Exploration
    14 Mar 2024 Hydromagmatic Pinnacles of the Steelhead Falls Area Geo-Exploration
    12 Nov 2023 Second Sesson Added: Fryrear Canyon Geo-Exploration II
    5 Nov 2023 Fryrear Canyon Geo-Exploration
    22 Sep 2023 Henkle Butte & Aspen Hollow Geo-Exploration
    22 Aug 2023 Tour Deschutes (River) Geohydrology Field Trip
    23 Jul 2023 Deschutes Formation Field Trip
    24 Jun 2023 Geohydrology of Siver Creek Field Trip, Harney Basin
    9 Jun 2023 Columbia Gorge Field Trip
    24 May 2023 Smith Rock Geo-Exploration
    26 Apr 2023 Session 2: Riley Ranch Field Trip
    21 Apr 2023 Riley Ranch Field Trip
    31 Mar 2023 Session 2: COGS Geo-Exploration: Barnes Butte, Prineville, OR
    31 Mar 2023 COGS Geo-Exploration: Barnes Butte, Prineville, OR
    12 Mar 2023 Steelhead Falls Geo-Exploration - Session 2
    11 Mar 2023 Steelhead Falls Geo-Exploration
    26 Oct 2022 Mafic Volcanism!
    30 Sep 2022 Thomas Condon Paleontology Center tour and field work experience
    17 Sep 2022 Deschutes Formation and Tumalo Volcanic Center Field Trip
    24 Aug 2022 Melting Glaciers, Failing Dams: The 1966 Debris Flow from No Name Lake Field Trip
    5 Aug 2022 Faults in the Strawberry Mountains
    1 Aug 2022 Whychus Creek Geo-Exploration
    26 Jun 2022 Lava Cast Forest Field Trip
    4 May 2022 COGS Geo-Exploration: Gray Butte
    7 Apr 2022 COGS Geo-Exploration: Barnes Butte, Prineville, OR
    3 Dec 2021 COGS Geo-Exploration: Farewell Bend Loop
    1 Dec 2021 COGS Geo-Exploration: Flatiron Rock in the Oregon Badlands
    6 Aug 2021 Ochoco Mining District Field Trip by Carrie Gordon & Derek Loeb
    28 Jul 2021 Deschutes River Geohydrology Field Trip
    27 Jun 2021 COGS Field Trip: Fault Scarps of Mt. Hood (south side)
    27 Mar 2020 Monthly Tours of the OSU-Cascades Pumice Mine
    4 Oct 2019 Deschutes River Field Trip
    14 Sep 2019 Mount Hood Field Trip
    22 Jul 2019 Newberry Volcano Field Trip
    13 Jul 2019 Wildcat Mountain Caldera Field Trip
    28 Jun 2019 Fire and Water: Recent mafic volcanism of the central Oregon Cascades
    16 May 2019 Geology of the Scout Camp loop trail along the middle Deschutes River
    27 Apr 2019 Geology of Shevlin Park
    3 Nov 2018 Hydrovolcanoes of Central Oregon Field Trip
    23 Oct 2018 Crooked River Caldera Field Trip
    23 Sep 2018 Mount Bachelor Volcanic Chain Field Trip
    14 Sep 2018 Clarno Fossil Beds Field Trip
    5 Aug 2018 Glacial Geomorphology of the Santiam Pass Area Field Trip
    14 Jul 2018 Lava Butte and Lava Lands Visitor Center
    10 May 2018 Deschutes Formation, Whychus Creek Geologic Field Trip
    1 Apr 2018 Geology of Riley Ranch Nature Reserve Field Trip

    Central Oregon Geoscience Society

    Email: COGeoSoc@gmail.com
    P.O. Box 2154,  Bend, Oregon 97709

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