Video by Bob Kroll

Welcome to Williams GeoAdventures! I pride myself in custom-designing GeoAdventures for folks who love geology, but we do so much more. By partnering with top-notch expert local guides, each trip combines not only fabulous geology and the beauty of the natural world, but offers experiences in each regions historic, cultural, and gastronomic delights. And we always have a lot of fun!

These trips are made for the geology enthusiast. I pick an existing trip or develop a new one and propose a time frame for offering that trip such as "September 2017". People contact me to be placed on the Interested Parties list for that trip. People on the list have the first opportunity to sign up for the trip. When enough people are interested, I finalize the trip dates and costs and announce the trip to the interested parties list and collect deposits. I then announce the trip to the general public to fill any remaining spaces. No previous geologic course work is required.

International trips


Dolo-Slovo Geology Field TripDolo-Slovo Rocks!
Exclusive for NWGS and Friends!
Ten Days in Late June‑Early July, 2019 | $3,980

The Dolo-Slovo Rocks! Trip visits three of the most amazing regions of North-eastern Italy and Slovenia: The Julian Alps Lake Bled and the Škocjan Caves of Slovenia, the Trieste/Carso (Karst) area, and the enchanting Dolomite Mountains.

Julian Alps - The Julian Alps are renowned for their scenic beauty, Slovenian culture, and gastronomic specialties.  We will also visit the World Heritage Site at the unforgettable Škocjan Caves in Slovenia.

Trieste and Carso area - Trieste has the beauty of the azure Adriatic Sea.  In this corner of Italy is the classical beauty of the Mediterranean landscape, tempered by the first hints of the Slavonic worlds, as well as the Alps, which provide an almost magical backdrop to the area.  The long-standing Austrian-Hungarian presence can still be felt in the air here, and has left many traces in the landscape, in the cuisine, and in the local customs.
The Carso is in fact one cultural and geographical entity, even though it now belongs to two different countries. It is a region known far and wide for its geological features – so important that they even gave their name to a whole series of geological phenomena (defined precisely as 'karstic').

Dolomite Mountains – The Dolomites capture the imagination for their stunning peaks seemingly coming out of the dark green of spruce forests.  The name 'Dolomites', almost speaks for itself as a synonym for "magical mountains", with remarkable geology, charming towns, and delectable fresh local food and wine, handpicked by out fabulous local guide Maximiliano Calligola.  The Dolomite Mountains are a UNESCO World Heritage Site.  We will experience many of the serial properties of the Dolomite World Heritage Site during our stay, including Tre Cime and Bletterbach gorge. 

The trip will include a series of highlights from all three regions. The majestic peaks of the Dolomites – with the immense views they offer, and the incredible experience of walking on what was once the bed of an ocean, will be complemented by the monumental caves we will see in the Carso and Slovenia. We will walk on historical trails, taking in the grandeur of nature as well as the cultural, artistic, historical and gastronomical plenty that these regions offer.   We are talking some memorable meals, folks – and did we mention the wines?

Details on the Dolo-Slovo Rocks! 2019 Trip  |  Contact Tom for more information

Western U.S. trips 


Yosemite-Eastern Sierra
September 12-16, 2018 | $500 Registration Open

Photos of the Yosemite/Eastern Sierra Geology Field Trip
Photos of the Yosemite/Eastern Sierra Geology Field Trip by Anne Leonard

The Yosemite and Eastern Sierra trip is a 5-day exploration of the Yosemite Valley and the Eastern Sierra from Bridgeport to Bishop, including Devil's Postpile, Bodie, Mono Lake, and the Long Valley Caldera.  The beauty and spectacular geology and landscapes of the Yosemite Valley are awe inspiring.  The Mammoth area is the most active volcanic area in the continental U.S. in the last million years and has some impressive glacial features.  We will even have the chance to soak in several hot springs!  Camping and lodging options are planned in both the Yosemite Valley and Mammoth Lakes area.

Details on the Yosemite/Eastern Sierra Geology Field Trip


California North Coast Geology Field Trip
October 26-28, 2018 | $450 Registration Open

Photos of the North Coast Geology Field Trip

Explore the remarkable geology along the coast north of San Francisco from Bodega Head to Mendocino in this three-day field trip, spending nights in cliff-top custom homes. Wave-cut platforms, rocky headlands and sea stacks, uplifted terraces, crashing waves, and wide sandy beaches are your outdoor classroom as you discover how the collision of ocean and land has shaped the shore. You explore rocks formed millions of years ago when the ancestral Pacific plate collided with the North American plate, leaving the remarkable and world-famous sequence of marine sedimentary and volcanic rocks called the Franciscan complex. You also investigate the impact of tectonic movements along the San Andreas Fault that are lifting the land and slowly sliding rocks to the west of the fault zone toward Alaska.

The itinerary includes Bodega Head, Mammoth Rock, and Fort Ross on the Sonoma Coast, and Anchor Bay, Bowling Ball Beach, Point Arena, and the Big River on the Mendocino Coast, as well as shorter stops along the way. Participants stay at one or two Irish Beach homes with stunning ocean views of Point Arena. There are numerous short hikes of up to two miles.

Details on the North Coast Geology Field Trip


Grand Canyon Geology TripGrand Canyon Raft & Rock

Upper Grand Canyon: July 24–29, 2019

Photos from 2018 Grand Canyon trip by Russ Powell

Imagine yourself on a raft on the Colorado River entering into Grand Canyon National Park. This could be you! What better way to raft and explore the Grand Canyon than with a geologist!

This trip includes a 6-day oar-powered rafting trip on the Colorado River into Grand Canyon National Park from Lees Ferry to Phantom Ranch. There is also a travel day before and after the trip.

Join me on an exciting journey back through geologic time. The rafting trip travels through progressively older rocks that span the entire Paleozoic Era as Marble Canyon deepens, before reaching the 1.8 billion year-old rocks of the Inner Gorge of the Grand Canyon. This is one-third of the age of the Earth! The geology trip reading assignments are on John Wesley Powell and his explorations of the Grand Canyon and the geologic history of the Grand Canyon and Colorado Plateau. The field trip focuses on geologic processes at work in the canyon, such as weathering, erosion, and mass wasting; depositional environments and sedimentary structures; geologic time and dating; faulting and folding; and igneous and metamorphic rocks. The trip includes a strenuous hike out of the Grand Canyon from Phantom Ranch to the South Rim and numerous daily side canyon hikes.

Details on the 2019 Grand Canyon Raft & Rock Trip

Private Half-Day or Full-Day Geology Field Trips
Along the Marin and Sonoma Coast from the Marin Headlands and Point Reyes to Salt Point State Park I would love to design a short trip for your family or group. Price negotiable based on group size.
Contact Tom for details

Past Trips

Grand Canyon Raft & Rock July 2018

Dolo-Slovo Rocks! June/July 2018

Scotland Rocks! II – The Islands of the West June 2018

New Zealand Rocks! December 2017

Geology of Lassen Volcanic National Park September 2017

Grand Canyon Raft and Rock August 2017

Scotland Rocks! June 2017

Geology of Death Valley National Park March 2017

California North Coast Geology Field Trip September 2016

Grand Canyon Raft and Rock August 2016

Iceland Rocks! GeoAdventure July/August 2016

Scotland Rocks! II – The Islands of the West June 2016

Yosemite-Eastern Sierra Geology Field Trip September 2015

Scotland Rocks! Geology Field Trip June 2015

Italy Rocks! GeoAdventure June 2014

California North Coast Geology Field Trip March and September 2014

Eastern Sierra Geology Field Trip October 2013

Yosemite/Eastern Sierra Geology Field Trip October 2012

Scotland Rocks! Geology Field Trip July 2012

Geology of Grand Canyon National Park June 2011

Geology of Death Valley National Park April 2011