ELK ROCK ISLAND TOURS

with GARRET ROMAINE

SEPTEMBER 12 OR 13, 2026, 9:45 Am TO 12:00 PM

Elk Rock Island Field Trips

September 12 and September 13, 2026 (two separate, identical trips)

Embark on a two-hour geological field trip at the Elk Rock Island city park in Milwaukie, Oregon and gain insights into local and regional geological processes. Identical trips will be offered on Saturday and Sunday, so choose the date that works for you. This locale features the 40-million-year-old Basalt of Waverly Heights, a remnant of the late Eocene volcanic rocks that existed before the Columbia River Basalt flows flooded the area. Elk Rock Island is an excellent touchstone for discussing regional and Portland geology, enabling coverage of the Portland Hills, local volcanism, Missoula Floods, and more. 

This discussion covers some of the greatest geologists that have unraveled Oregon’s complex terrain. We’ll start with Dr. Thomas Condon (1822–1907), Oregon’s first state geologist, who first described the Portland submergence zone. The talk will also cover Dr. J. Harlan Bretz (1882–1981), whose ground-breaking work on Missoula Floods paved the way for geologists to unravel reversed bedding in Willamette River gravels near this area. We’ll also include more recent geological studies on the faults and outcrops of the area, including the work of Rudy Tschernich (1945–2017) author of Zeolites of the World, who sampled these rocks.

In addition to the Waverly Heights Basalt, the local area geology includes basalts from the Columbia River Basalt group, Tertiary gravels from the Willamette River system, baked contacts between lava flows, columnar jointing in the basalt columns, and gold-bearing black sands at the beach on the north end of the island. The discussion will tie in the complex faulting of the Portland Hills to regional faults and the Yellowstone Hot Spot.

Whether you're a seasoned expert or a curious explorer, this field trip is a must-attend! Engage in lively discussions, examine awe-inspiring rock exposures, and gain insight into the dynamic forces that have shaped the region. Leading the expedition is Garret Romaine, a retired field guide writer and past executive director of the Rice Northwest Museum of Rocks and Minerals. Garret will bring the landscape to life with insights into tips for local rockhounds and gold prospectors. Parking for the Elk Rock Island city park is limited, and you may end up parking a block or two away from the trailhead. The walking tour will end at noon. Although parts of the trail are paved, this walk is, unfortunately, not wheelchair-compatible.

REGISTRATION

Registrants must be GSOC members, and each registrant is allowed to bring one guest. This trip will be registered on a first-come, first-served basis. Registration for general membership will begin on August 22, 2026.

PARTICIPATION, FEES, CANCELLATIONS

Each of these trips will be limited to a maximum of 20 participants. Participants are responsible for providing their food, lodging, and transportation. The trip fee of $50 will cover the trip field guide, special use permit, a small donation to the Bev Vogt scholarship fund, and GSOC overhead costs. Guest fee will be $35 and does not include a printed copy of the field guide. TRIP FEES ARE NON-REFUNDABLE. All participants will be required to sign liability waivers for GSOC at the meeting area for the trip.

TRANSPORTATION

These trips will be walking tours at a single location, and participants are responsible for arranging their own transportation. Carpoolers should help offset their drivers' costs.

LODGING

This trip will not require lodging for Portland area residents. Out-of-towners should make refundable reservations for lodging in case we would need to cancel the trip for any reason.

FOOD

Participants are responsible for their food (i.e., lunch) and water for the trip. The city park has plenty of room for lunch and has a portable restroom.

TRIP SAFETY

For their safety, we require that all participants wear clothing suitable for the climate and rocky terrain, including sturdy, closed-toe shoes or boots. Walking sticks are advised for older participants. Participants engaging in rock hammering (as permitted by the trip leader) or observing rock hammering must wear safety goggles provided by GSOC. No participant may engage in risky activities, such as climbing steep rock outcrops or navigating excessively steep or treacherous terrain. Participants must not leave the group on hikes unless accompanied by another participant selected by the group leaders.

These trips will have a trip organizer and safety observers. Please bring any questions about trip logistics to the organizer. Please bring water, layers of clothing, sturdy boots or shoes, walking poles, hats, and sunscreen on this trip. Please be aware that ticks may be an issue at this time of year, so be sure to check yourself and your clothing carefully after the trip. Poison oak has been spotted here as well. STAY ON THE TRAILS!

CONTACTS

For more information, email Garret Romaine (gromaine3@gmail.com).

Geology of the sandy river canyon

with Ian Madin
September 22, 2026, 9 am to approximately 3 pm

This one-day trip features a moderate to difficult hike into the Sandy River Canyon across the river from Oxbow Regional Park. Along the hike down into the canyon, GSOC members will pass through old landslides along the canyon walls and arrive at scarps of Troutdale Formation and Sandy River Mudstone, both products of the Columbia River system during the Pliocene, sandwiched between younger basalt above and Rhododendron Formation sediments and Columbia River Basalt below.

Our trip guide will be Ian Madin, the chief scientist at the Oregon Department of Geology and Mineral Industries for many years, now retired. Ian will lead the trip down the wall of the canyon, stopping at several outcrops enroute to one of the most fascinating waterfalls you will see in the state of Oregon. The outcrops viewed will give the participants a chance to view close-up multiple facies of the Troutdale Formation and discuss the origins of the materials that compose this sedimentary output of the Columbia River system. Interlaced with the Troutdale is the Sandy River Mudstone, which is also a product of the ancestral Columbia River, which flowed through this area during the Pliocene.

Due to the quality of the trail, which is narrow in some places with steep drop-offs, wet and muddy with spring water in other places, we ask that no members with heart problems, shortness of breath, dizzy spells or vertigo go on this trip. We will also require that everyone attending be attired in long pants and hiking boots. In some places poison oak lines the trail. Hiking poles are also recommended. A couple of the outcrops also have steep approaches. Having said all that, the overall elevation loss and gain on this 2-mile round trip trail is only about 300 feet, so navigating these hazards should not overly wind someone of reasonable fitness.

REGISTRATION, PARTICIPATION, FEES, CANCELLATIONS

Registrants must be GSOC members, and each registrant may bring one guest. Due to trail hazards minors will not be allowed on this trip. This trip will be registered on a first-come, first-served basis. Registration for general membership will begin on Monday, August 31, 2026. Fee is $45 for main registrants. Guest fee will be $35 and does not include a printed copy of the field guide. TRIP FEES ARE NON-REFUNDABLE.

This trip will be limited to a maximum of 12 participants. The trip fee will cover the trip field guide, reconnaissance expenses, a small donation to the Bev Vogt scholarship fund and GSOC overhead costs. All participants will be required to sign liability waivers for GSOC at the meeting area for the trip.

TRANSPORTATION

This trip will be a carpool/caravan style trip, and participants are responsible for arranging their own transportation. Carpoolers should help their drivers with the cost of fuel.

LODGING

This trip will not require lodging for Portland area residents. Out-of-towners should make refundable reservations for lodging in case we would need to cancel the trip due to foul weather (making the trail even more hazardous).

FOOD

Participants will provide their own sack lunch and drinks. We will eat lunch at the waterfall at the half-way point in the hike.

TRIP SAFETY AND ATTIRE

For their safety, we will require that all participants be attired in long pants and hiking boots. Participants engaging in rock hammering (where allowed by the trip leaders) or observing rock hammering must wear safety goggles supplied by GSOC. Participants are also required to wear GSOC safety vests on stops with traffic hazards and stay off roadways with fast or busy traffic unless crossing safely. No participant may engage in risky activities such as climbing steep rock outcrops or negotiating excessively steep or wild terrain. Participants must not leave the group on hikes unless accompanied by another participant selected by the group leaders.

The trip will have a trip organizer and safety observer. Please bring any questions about trip logistics to the organizer. In addition to requiring participants to adhere to safety guidelines, the safety observer will assist participant drivers in staying on the trip route.

Please bring plenty of water, above-mentioned long pants and boots, hand lens or magnifying glass, walking poles, hats, and sunscreen on this trip. And possibly bug spray. Don’t forget to throw outer clothing in the wash after the trip in case it contacts the poison oak.

CONTACTS

For more information email Carol Hasenberg (fieldtrips@gsoc.org).

GSOC Fall Trip to Malheur with Dr. David Sherrod

Hosted by Malheur Field Station

October 2-5, 2026

Fee $910

Join GSOC’s fall trip to Malheur Field Station with Dr. Dave Sherrod! Enjoy two full days in the field exploring the geology of the region! 

This all-inclusive adventure includes your lodging for 3 nights, complete meals - cooked fresh daily, along with transportation during the trip. 

You'll be staying in one of the field station lodges. Lodging will be 1-3 people per room in our E-dorm unit, with separate bathroom/shower facilities for men & women. 

You will need to provide your own transportation to and from the Malheur Field Station in the Malheur National Wildlife Refuge south of Burns, Oregon. Arrival on Oct. 2 - Check in from 4-6pm. Dinner and Meet 6:30 pm. 

Program will begin on October 3 with a tour of Wrights Point and the Narrows. October 4 the tour will continue with Diamond Craters. Transportation will be provided October 3 and 4 by Malheur Field Station.  On October 5 Malheur Field Station will provide breakfast and participants will check out by 11am.

Please plan to bring: sheets & blanket and/or sleeping bag for a twin size bed, a pillow, towel, water bottle, and sun protection along with any suggested geology items! 

Delicious, homemade meals included - hot breakfast, hearty bag lunches for days in the field, and 4 course dinners. Transportation included during the program. 

Cancellation Policy: You will receive a 100% refund if you cancel on or before September 18th, 2026. If you cancel after September 18th, you will receive a 50% refund. If you cancel after September 28th, you will receive a 25% refund. 

Any questions? Please reach out to Malheur Field Station director, Elizabeth Basa. 

541-493-2629 / malheurfieldstation@gmail.com