Field Trips

Each year the IMMG conducts field trips to geologic and mining points of interest. Led by university professors, local geologists, and knowledgeable enthusiasts, these wildly popular field trips are a unique opportunity to learn more about the history of our State and adjoining regions. And, they are great family fun!

Cost is $10 for IMMG members, $15 for non-members. Don’t forget members get one free field trip! Most field trips take up the good part of the day so always come prepared with plenty of food and water, and dress for all weather possibilities.

Below is our 2017 Field Trip schedule. If you have any questions, contact our Field Trip Coordinator Steve Cox at 853-1678 or cell          208-724-4679

2017 Field Trips

April 15: Fluvial Effects of the Bonneville Flood

We will join Professors Paul Link and Ben Crosby on an Idaho State University field trip to examine flood effects from the Bonneville Flood. Sites will include the Milner Dam, Cauldron Linn, the Snake Canyon at Twin Falls and Box Canyon (part of Thousand Springs State Park). There is a fascinating mystery about Box Canyon and nearby Malad Gorge – current surface features do not identify sources of water sufficient to account for the degree of erosion to account for them. Dr. Link may solve the mystery!

Because of travel distance to the meeting site, we will register early at the Museum at 7:00 AM with a departure at 7:30 AM. Heading east on the Interstate, we will have a rendezvous and rest stop at the Bliss Rest Area and then meet Dr. Link at the Milner Dam overlook at 10:00 AM. There will be some walking on uneven surfaces; good field shoes or hiking boots are MANDATORY – no sandals, flip-flops or smooth-soled street shoes. Early in the year, this area can be very windy and cold; appropriate clothing for the weather will be important. Bring water and lunch. The only rest area after Bliss will be at Milner; comfort with “field latrine” protocols will be important. Depending on site visit schedules, the trip will end at 6:00 PM; however, early departure will be an option for those who have evening commitments in Boise. No registration required.

Here are the field trip handout and article about Box Canyon:

Milner Field_Trip_Guide2017_v2_lg      Amidon and Clark, 2014 GSAB

May 20: Owyhee County Fossils

Field Trip Coordinator Steve Cox will lead to visit some of our favorite fossil stops in Owyhee County: the Algal Reef, the Bruneau Woodpile for petrified wood and concretions and the Rye Patch Road site where a number of fossils have been discovered by BSU students. As a big bonus, Coyote Short PG, the IMMG licensed professional geologist, will act as the expert in identifying strata and fossils!

We will meet at the Museum for registration at 7:30 AM with a prompt departure at 8:00 AM. We will rendezvous and have a rest stop at the Bruneau City Park. This could be an alternate registration site at about 9:15 AM. “Field latrine” conditions will prevail after we leave Bruneau. Dress for the weather, bring lunch and water.  Return to Boise by 5:00 PM, or earlier if necessary. No preregistration needed. A note on equipment: bring geologic hammers, cheap strainers (if you can sneak them past your wife – IMMG will bring about 6), trowels to scrape the outcrops into the strainers, loupes to look for small fossil bits. A note on collecting: vertebrate fossils can NOT be collected on public lands. They can be identified and examined, but must be left in situ. Invertebrates, including mollusks, can be collected in “reasonable amounts” as can petrified wood and leaf impressions.

Special Note on Vehicle Suitability:  Bruneau Woodpile is best accessed by high clearance/all-wheel drive vehicles. We can stage to a certain point and then transfer people from sedans to seats in high clearance/all-wheel drive vehicles for the final distance. It would be helpful for as many participants as possible to bring high clearance/all-wheel drive vehicles to provide space for those that do not have such a vehicle. Weather immediately prior to the trip date may impact access to locations (because of the famous “Owyhee gumbo”) and that can only be determined on the day of the trip.

UPDATE: Our scout trip on 5/14 found that the access to Horse Hill Beach has been obscured by a lush growth of cheatgrass, so we will have to skip that site. Instead, we will visit two sites at the Woodpile as well as the Reef and Rye Patch Road. Some pertinent information is attached below and it would be helpful if you print your own copies, if possible. I will bring a few to the trip.

Algal Reef Structure    Time Scale    Tectonic Map of Idaho    Lake Idaho Sediments    Geologic Map Idaho    Fish Fossils

June 17: Gold Panning Moved to August

Special Announcement:  because of high flows in all Boise River watershed streams and rivers, the field trip to Don Adair’s claim on Grimes Creek has been moved to August. Don has not been on his property since the deep snows started and can not be sure that the footbridge access to his property is still passable, or what the flows will be in June and what impacts on his facilities have occurred. Moving the trip to August will ensure that Don will have time to repair the bridge and any other damage and flows will have moderated.


July 22: U. S. Geothermal plant at Neal Hot Springs, west of Vale, OR, Roy Mink, leading

We are lucky to have one of the most innovative geothermal plants in the US just over the Oregon state line. World-wide acclaimed geothermal expert, long-time IMMG member and USG corporate board member Roy Mink has facilitated this repeat visit to the Vale plant. When last visited in 2015, the participants were awed by the recirculating technology used for electrical generation with almost no environmental impact. This is an amazing example of geology and technology coming together and IMMG is proud to be allowed to show it to the public. 

There are a few rules. Sturdy hiking shoes or boots are REQUIRED, full length pants and shirtsleeves are REQUIRED because this is an active industrial site (NO sandals, street shoes, shorts, t-shirts). Pre-registration is REQUIRED to allow USG to appropriately staff the site. This is a high noise environment, hearing protection (ear plugs) will be provided, but special needs participants may want to bring noise-cancelling headphones in addition.  Call Steve Cox at 208-853-1678 or 208-724-4679 for pre-registration.

After July 15, please call Clint Cuzzo to pre-register at 208-850-1238.

We will sign-in at the Winco parking lot on Meridian Road at I-84 at 7:30 AM with a prompt departure at 8:00 AM. We will reassemble and have a rest stop at the big rest area just over the Oregon state line (this could be an alternate sign-in site for west valley residents). We will then proceed on I-84 to Exit 374 onto Hwy. 30/201, proceeding south to the intersection of Hwy. 26 west to Vale. We will rendezvous again at the Vale Sinclair gas station/food shop/rest stop before heading west to Greenfield Road (Right), Grantham Blvd. (Left) and Bully Creek Road (Right) to the plant site.

The orientation, plant tour and geology tour will complete around 3:00 PM. There are restrooms and water will be available at the USG plant. It will be warm at this time of year; bring water, lunch and dress  appropriately.  Return to Boise by  about 6:00 PM.

A link to a presentation about the plant can be seen at: http://www.searchanddiscovery. com/documents/2017/ 80584warren/ndx_warren.pdf

Aug 12: Gold Panning and Boise Basin History

Our always popular leader and raconteur Don Adair will host us at his gold claim on Grimes Creek to see if we can find the “real stuff.” Don provides gold sands to the Museum for our Gift Shop and for panning events such as the Rock Party. We will also learn about the history of mining in the Boise Basin and may take some short side trips to visit mining ghost towns in the area. Outhouse is available on site at the claim. No vehicle restrictions. IMMG will provide gold pans for those that do not have them and Don has some on site also.

Register at the Museum at 7:30 AM with a departure at 8:00 AM. We will rendezvous at Idaho City for a rest stop at the visitor center and the proceed up to Grimes Creek. Bring lunch and water, dress for the weather. Don recommends rubber boots, if you have them, and clothes you don’t mind getting dirty. He has also generously offered to let you collect a bucket of gravel to take home and pan there – bring a container (bucket or plastic bag). You can leave when you fill your poke! No registration required

September 9: Leslie Gulch with retired Oregon State geologist Mark Ferns.

This is a wonderland of sculpted rhyolite and an exciting destination for geology enthusiasts. We will register at the Winco Parking lot at Meridian Road and I-84 at 7:30 with an 8:00 departure. We’ll meet Mark at the big ION gas station at the junction of Highway 55 and US 95 west of Marsing. This will also be a rest, gas and supply stop. As always, dress for the weather, bring lunch and plenty of water. Some, but not long distance, walking is anticipated. No reservation required. Return to Boise is at your option, but the driving time from ION to the Gulch is about 1 hour, 45 minutes, so plan accordingly if you have an evening commitment.

There is a comprehensive article about volcanic activity in southwest Idaho and southeast Oregon, including the Leslie Gulch area at:

Mark Ferns is the lead author.

October 21: Balanced Rock and Unstable Ground, led by Distinguished Professor Shawn Willsey of CSI. 

Shawn is one of our most highly acclaimed leaders and his knowledge, preparation and enthusiasm are what led to his Distinguished Professor award. We will visit Balanced Rock west of Buhl, a famous Idaho geologic location, and then visit the Bluegill Landslide on Salmon Falls Creek and the Bliss Landslide and lava dam on the Snake River to consider the geologic and geomorphologic factors that lead to landslide instability. I am sure we will learn much new information, even though we think we know about landslides. There is a short hike across some rocky ground to visit Balanced Rock, otherwise not much walking will be required, but good shoes/boots are always highly recommended. As usual dress for the weather, bring lunch and plenty of water.

We will register at the Museum at 7:30 with a departure at 8:00 sharp. There will be a potty stop at the Bliss Rest Area before we leave the Interstate to meet Shawn at the Arctic Circle in Buhl. No reservation required. Return to Boise starting about 4:00 PM

There is an article about the Bluegill Landslide at:

Visit field trips from the past:

2012 Field Trips

2013 Field Trips

2014 Field Trips

2015 Field Trips

Find other field trip information:

Field Trip Resources from the Web