Upcoming Field Trips

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• Tour de Tuyas Geo-Exploration, Session 1

  • When
    24 Jul 2026
  •  
    9:00 AM - 12:30 PM
  • Location
    Santiam Pass PCT Trailhead
  • Spaces left
    0

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  Tour de Tuyas Geo-Exploration, Session 1

  Led by Derek Loeb

  Friday, July 24, 9:00 AM - 12:30 PM

  Tuyas are flat topped, steep sided volcanic features that are interpreted to have erupted while capped by significant thickness of glacial ice.  The Santiam Pass area is one of the best places in the world to easily view these features.

  We will meet at the Santiam Pass, PCT Trailhead and after introductions and a geological orientation we will hike just over a mile while gradually gaining about 350 feet of elevation.  Along the way we will have great views looking south at our local examples of Tuyas, Hayrick Butte and Hogg Rock.  Our destination is an unnamed topographic feature 'No Name Knob' which may be a small Tuya.  ('No Name Knob' is my the working name for this feature but  temporary naming rights are available - submit your proposed name & bid in the form of a pledge to donate to COGS.)

  Total mileage will be about 2.5 miles with a gradual elevation gain of plus/minus 350' on a good trail.  This area has been burned so there is not much shade or wind breaks.  This trip is very much view dependent so low clouds or very bad smoke conditions may lead to a cancellation.  Because we will be in a wilderness area,  participants is limited to 12.  Participants must be a member of COGS or a guest of a member. As always please leave your pets at home as they are not allowed on COGS field trips.

  Ride Sharing:  I am looking for a volunteer to informally be the ride share coordinator for this trip.

  Please contact Derek Loeb ( DerekLoeb@gmail.com ) with any questions.

  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.  If the trip is full, please join the wait list.
  

  
  

  
  

   
  
  

  
  

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• Tour de Tuyas Geo-Exploration, Session 2

  • When
    24 Jul 2026
  •  
    1:00 PM - 4:30 PM
  • Location
    Santiam Pass PCT Trailhead
  • Spaces left
    4

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  Tour de Tuyas Geo-Exploration, Session 2

  Led by Derek Loeb

  Friday, July 24, 1:00 PM - 4:30 PM

  Tuyas are flat topped, steep sided volcanic features that are interpreted to have erupted while capped by significant thickness of glacial ice.  The Santiam Pass area is one of the best places in the world to easily view these features.

  We will meet at the Santiam Pass, PCT Trailhead and after introductions and a geological orientation we will hike just over a mile while gradually gaining about 350 feet of elevation.  Along the way we will have great views looking south at our local examples of Tuyas, Hayrick Butte and Hogg Rock.  Our destination is an unnamed topographic feature 'No Name Knob' which may be a small Tuya.  ('No Name Knob' is my the working name for this feature but  temporary naming rights are available - submit your proposed name & bid in the form of a pledge to donate to COGS.)

  Total mileage will be about 2.5 miles with a gradual elevation gain of plus/minus 350' on a good trail.  This area has been burned so there is not much shade or wind breaks.  This trip is very much view dependent so low clouds or very bad smoke conditions may lead to a cancellation.  Because we will be in a wilderness area,  participants is limited to 12.  Participants must be a member of COGS or a guest of a member. As always please leave your pets at home as they are not allowed on COGS field trips.

  Ride Sharing:  I am looking for a volunteer to informally be the ride share coordinator for this trip.

  Please contact Derek Loeb ( DerekLoeb@gmail.com ) with any questions.

  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.  If the trip is full, please join the wait list.
  

  
  

  
  

   
  
  

  
  

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• Harney Basin Field Trip

  • Start
    9 Oct 2026
  •  
    6:00 PM
  • End
    11 Oct 2026
  •  
    4:00 PM
  • Location
    Malheur Field Station, Princeton, OR
  • Spaces left
    11

  
  

  
  

   

  
  

  Harney Basin Field Trip

  Led by Dave Sherrod

  Friday, Oct. 9, 6:00 PM - Sunday, Oct. 11, 4 pm

  Please join Dave Sherrod on a two day exploration of the Harney Basin, south of Burns.  We’ll assemble Friday evening (10/9, Day 0) at Malheur Field Station, with field Day 1 on Saturday and Day 2 Sunday (10/10, 10/11).  Day 1 will explore the basin’s stratigraphy, structure, geomorphology, and lake history from middle Miocene time to present (road stops). Day 2 is devoted to Diamond Craters, a Holocene lava field with a fascinating complex history unlike any other in the western mainland U.S. The Diamond Craters day includes driving stops and a lunch stop at a viewpoint overlooking the craters.  Participants have the option of ending the trip here but there is a recommended, but optional, walking tour of the central crater complex, in the heartland of Diamond Craters.  This walk is cross country totaling about a mile with modest elevation loss/gain of 200'.  The footing is generally good but footwear with good traction are recommended as well as hiking poles if you find them helpful.

  This announcement is posted earlier than usual for COGS trips because early commitment and payment will be needed. The trip is too far from Bend to allow a Bend-based start each day.  Malheur Field Station, 30 miles south of Burns, will  be our accommodations which feature rooms with two twin beds/room at $50/night/person and a full dinner ($25) Friday and Saturday nights. There is also an option for up to three self contained RV sites at $35/nights.  Participants could also stay or camp offsite.  There will be a cap of 25 total participants.

  More information on the Malheur Field Station is provided on this info sheet:

  Malheur Field Station Visitor Guide.pdf

  Participants must be a member of COGS or a guest of a member. As always please leave your pets at home as they are not allowed on COGS field trips.

  Ride Sharing:  Details to be determined.

  This is a 'Save the Date' announcement.  Additional details and the registration process will be provided closer to the date.

  
  

  
  

   
  
  

  
  

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