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Snake River Plain and Albion Mountains Field Trip


Granite of the Almo Pluton, City of Rocks National Reserve, Albion Mountains: Jim Sage Mts. (dark ridge in background)

Granite of the Almo Pluton, City of Rocks National Reserve, Albion Mountains: Jim Sage Mts. (dark ridge in background)

The Snake River Plain and Albion Mountains: A Diverse Geologic Museum

This car caravan/carpool field trip will focus on the diverse geology of Idaho’s Snake River Plain and the granitic core and the exterior ‘skin’ of the Albion Mountains/Middle Mountain region. The trip will be based in Boise for three nights (June 2, 3, 7) and Twin Falls for three nights (June 4, 5, 6). Participants will rendezvous in Boise the morning of June 3 after traveling from Portland the previous day. Some light walking/hiking will be on the agenda (maximum 1.6 miles one way) and moderate elevation gain (approx. 200 ft.). Most travel will be on paved roads but also there is about 46 miles of good quality gravel, four miles of graded dirt track, and two miles of a dirt track with a few patches of ruts and rocks, which is negotiable by normal clearance vehicles.

Our Itinerary includes:

  • overview of Snake River Plain geology,
  • Pleistocene shield volcanoes Kuna Butte and Initial Point and Hydrovolcanic vents
  • Sinker, Walters, White and Guffey Buttes,
  • Bonneville Flood Melon Boulders on Walters Bar,
  • Petroglyphs at Celebration Park,
  • local Boise geology from Table Rock
  • fossil algal reef
  • hot spring limestone
  • former shoreline habitat of Lake Idaho,
  • Bruneau Canyon and Dunes,
  • Malad Gorge and Box Canyon,
  • the Snake River Aquifer at Niagara and Crystal Springs,
  • cold springs along the Snake and fish propagation (a connection between geology and the fisheries industry) 
  • economic geology of a premiere stone industry in Idaho,
  • City of Rocks National Reserve with intrusive rocks dating 2.65 billion years,
  • Shoshone Falls – a geologic window into the Central Snake River Plain,
  • geologic art – rock sculptures of Black Magic Canyon of the Big Wood River,
  • The Little City of Rocks
  • rheomagmatic rhyolites
  • Mount Bennett Hills,
  • Camas Prairie,
  • lavas of Black Butte Crater
  • the recent ‘course adjuster’ of the Big Wood River
  • Hagerman Fossil Beds National Monument
  • land sites and a river's perspective
  • rafting the Snake River through the Monument,
  • natural dams on the Snake River
  • McKinney Butte Basalt (and Yahoo Clay)
  • the Bliss Landslide.

As you can see, this will be a week packed full of geologic wonders!

Bonneville Flood boulders on Walters Bar. Guffey Butte, a basaltic maar, is in the background.

Bonneville Flood boulders on Walters Bar. Guffey Butte, a basaltic maar, is in the background.

The trip will be lead by GSOC members Dave Olcott and Bo Nonn. Guest lecturers/leaders will include Dr. Terry Maley, retired distinguished geologist; Greg Osterhout, Vice President and CEO, Northern Stone Supply; and Shawn Willsey, Professor of Geology, College of Southern Idaho.

If you wish to participate in this field trip, please contact Dave Olcott at (503) 695-5219, daveolcott46@yahoo.com or Bo Nonn at (503) 691-4129, bononn14@q.com. A formal registration form will be available online and in the newsletter starting in January 2018. Participation will be limited, and participants will be selected on a first come, first served basis. Payment of fees must be completed by the GSOC banquet on March 11, 2018. All participants must be GSOC members or a guest of a member.

Trip fee is $100, and does NOT include transportation, lodging, meals and an optional rafting trip. Participants must arrange their own transportation, lodging and meals. An additional fee will be rendered for the geologist-guided raft trip through Hagerman Fossil Beds National Monument. An estimate for this fee is $50.00 per person. This fee will be paid directly to the outfitting company (details will be forthcoming).

If you’re planning to reserve your lodging early, here are some suggestions by Dave:

The following facilities permit tents:
    •  Boise/Meridian KOA: good access to the freeway
    •  Boise Riverside RV Park
    •  KOA Jerome: a few miles north of Twin Falls
    •  Oregon Trail RV (Twin Falls).

In Boise we will establish a rendezvous site for morning departures near Motel 6 and Inn of America, in the same area there are other motels (i.e. Best Western, Quality Inn, Super 8, Holiday Inn, etc.). In Twin Falls, we will rendezvous at the Twin Falls Visitor Center. Your proximity to these two rendezvous locations will save you time in the mornings. The advantage of both sites is they have good access to freeways and main highways and will allow us to get into the field in a reasonable time frame.