Hoffer Lake

EOU Glacial Geology class at Hoffer Lake (2011)


We have learned a tremendous amount about the geology of Eastern Oregon in the past few years thanks to the work of the Oregon Department of Geology and Mineral Industries and the faculty and students of Boise State University, Portland State University, Whitman College, the University of Oregon, Oregon State University, Washington State University, Eastern Oregon University, and others.

The intent of Eastern Oregon Geology is to provide an on-line journal where new discoveries, particularly those by undergraduate students, can be highlighted and made available to a larger audience.  We welcome your comments and suggestions for improvement!

Jay Van Tassell, Editor
Eastern Oregon Geology
Science Department- Badgley Hall
Eastern Oregon University
La Grande, OR 97850-2899
541-962-3351; 541-962-3873 (fax); jvantass@eou.edu


VOLUME 1.  Gravels.  January 2002

 Editor’s Note:  John Eliot Allen wrote about the Paleocene auriferous paleotorrent in Northeast Oregon.  These papers focus on gravels that may have great significance to understanding stream flow in the Grande Ronde Valley area during the Miocene.


Adam Isaacson, Sedimentology of the Catherine Creek Lane Gravels, northeast Oregon


Drew Sherman, Flow direction of late Miocene basalt and metaquartzite river deposits in the Starkey area, northeast Oregon


VOLUME 2.  Wallowa Lake.  September 2005

Editor’s note:  This issue is devoted to the EOU Geology program’s studies of Wallowa Lake which have been made possible due to the generosity of Eastern’s former president and first lady, David and Carolyn Gilbert.  The Gilberts provided us with their boat, lodging, and meals, plus lots of stimulating conversation, making this a wonderful place to do research.  Along the way, our students have figured out how to digitize depth data, program it into MapInfo and Vertical Mapper, and produce beautiful color charts of the lake floor.  And, they have learned that equipment often breaks and how ingenuity and resourcefulness play an important role in fieldwork.  We’ve learned a lot, but, as with all good research, we’ve revealed even more about what we don’t know about the floor of Wallowa Lake.  Enjoy!


Bryce Budlong, J.R. Collier, Calvin Davis, Rob Ledgerwood, and Jay Van Tassell, Bathymetry and sediments of Wallowa Lake, Oregon


VOLUME 3. Sediments and Fossils of the Powder Valley. December 2006

 Editor’s note:  The discovery of fossils behind the Always Welcome Inn in Baker City, Oregon, has led us to study the Miocene and Pliocene deposits of the Powder Valley and their connection to Lake Idaho..  We’re trying hard to learn more vertebrate paleontology and are enjoying working with paleontologists across the country as we struggle to understand what these fossils and sediments are telling us.


Ben Zublin, The geology of the lower half of the Powder River Canyon between Thief Valley Reservoir and the lower Powder Valley, Baker County, Oregon


Rob Ledgerwood, Late Miocene sediments of the Keating Valley, Oregon

Editor’s Note:  The 8.6 +/- 0.1 Ma ash described in this paper has been traced to the Twin Falls volcanic center in the Snake River Plain by Nash and Perkins (Oct 2012, Plus One, v. 7, no. 10, p. 1-13) and is not the Prater Creek Tuff!


Elizabeth Burton and Jay Van Tassell, Fossil beaver (Dipoides) tooth, Always Welcome Inn, Baker City, Oregon


April Leithner and Jay Van Tassell, Pliocene vole fossils, Always Welcome Inn, Oregon


Jayson Kisselburg, A semi-quantitative analysis of the distribution of fossils in the upper third of the Always Welcome Inn sequence, Baker City, Oregon


Eric Bergey, Misty Davis, Jayson Kisselburg, April Leithner, Story Miller, Carli Morris, Takeshi Sugimoto, and Jay Van Tassell, Pliocene (Blancan) voles at the Always Welcome Inn fossil site, Baker City, Oregon:  A study in progress



VOLUME 4. A Guide to the Fossils at the Always Welcome Inn, Baker City, Oregon, June 2007

Editor’s note:  Thanks to the help of paleontologists across the country, we’ve made a lot of exciting new discoveries at the Always Welcome Inn over the past five years.  This guide is a progress report written to let people know what we have found and what we know we don’t know about this exciting fossil fauna.


Kate Asplund, Eric Bergey, Misty Davis, Brooke Garton, Bryan Grimshaw, Allison Kuenzi, Story Miller, Carli Morris, KelseySwanson, Corby Weyhmiller, and Jay Van Tassell, A Guide to the Fossils at the Always Welcome Inn, Baker City, Oregon.



VOLUME 5.  More Finds at the Always Welcome Inn, Baker City, Oregon, November 2007

Editor’s note:  The students from Pine-Eagle High School found some exciting things when they came to the Always Welcome Inn last spring.  Here’s a report on the Castor jaw found by Adora Brockman.


Adora Brockman, Troy Tubbs, Story Miller, and Jay Van Tassell, Early Pliocene (Blancan) Fossil Beaver (Castor) Jaw Found at the Always Welcome Inn, Baker City, Oregon      


VOLUME 6.  Lupherella and Always Welcome Inn Ophiomys and Pollen Winter– Spring 2009

Editor’s note:  A Paleontology class project and two paper that began as a senior thesis!  This is our first attempt at pollen analysis– please let us know how we did


Candice Burnette, James Dittrick, Rustin Freeman, Kelsey Swanson, and Jay Van Tassell,  Early Jurassic (Pliensbachian) Lupherella abundance zone, Hurwal Formation, southern Wallowa Mountains, Northeast Oregon

Editor’s note (December 2012):  Dr. Chris McRoberts of SUNY Cortland e-mailed to let us know that these bivalves are Upper Triassic Halobia, not Lupherella.  There may be two Halobia species present.  One  is Halobia septentrionalis Smith, which would make the locality uppermost Carnian in age.  The ammonites appear to be Arietoceltites and possibly a tropitid, which also confirms the Late Triassic Carnian age. 

We have also found a second site which we believe contains Otapiria, which has also been found in the Triassic.  Stay tuned!


Misty Bork, John Rinehart, and Jay Van Tassell,  The Early Pliocene Ophiomys and the migration of Ophiomys into the Pacific Northwest


Candice Burnette, Pollen analysis of an early Pliocene lignite layer, Always Welcome Inn, Baker City, Oregon



VOLUME 7.  The Always Welcome Inn Hypolagus– Spring 2010

Editor’s note:  This paper is the result of a discovery on a Historical Geology class trip to the Always Welcome Inn.  We finally found a diagnostic rabbit tooth!


Brannon Farner and Jay Van Tassell   The Always Welcome Inn Hypolagus



VOLUME 8.  The late Pleistocene Airport Lane Fossils–  September 2011

 Editor’s Note:  This volume features a paper describing the Ice Age fossils that were found near the La Grande Airport in January 2010.  An article written by Amber Glaze for The Observer was picked up by the Associated Press and featured in every major paper in the United States and on Oregon Public Broadcasting.  A follow-up article appeared in EOU’s alumni magazine, The Mountaineer.


Jay Van Tassell, John Rinehart, and Laura Mahrt     The late Pleistocene Airport Lane fossils



VOLUME 9.  Fish Fry and Gravels, Baker and Keating Valleys Spring 2012

Editor’s note:  We’ve started looking in more detail at the Always Welcome Inn sequence and making progress figuring out the origins of the gravel that unconformably overlies the Always Welcome Inn fossil beds.


Adam Stubblefield,  Early Pliocene Fish Fry layer, Always Welcome Inn, Baker, Northeast Oregon


Dino May, James Dittrick, and Jay Van Tassell,   Late Pliocene to Early Pleistocene Gravels of the Baker and Keating Valleys


VOLUME 10.  Northeast Oregon Gravels–  December 2013

 Editor’s Note:  The geology students and faculty at EOU have been studying the gravels in the La Grande and Baker City area for 15 years with the help of a lot of friends.  This seemed like a good time to pull it all together and see what we’ve learned so far.  Enjoy!

Jay Van Tassell, Drew Sherman, Adam Isaacson, Rob Ledgerwood, James Dittrick, Dino May, and Sandra Pilling  A Tale of Six Gravels, La Grande and Baker City area, NE Oregon