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


New Zealand Geology Field TripNew Zealand Rocks!
December 6-21, 2017 | $6,400  Registration Open

Photos from New Zealand Scouting Trip
A 15-day exploration of the North and South Islands of New Zealand, a country with stunning and diverse natural beauty, with me and outstanding Australian geologic guide Paul Ashley. New Zealand has spectacular landscapes, with soaring peaks, rolling pasture land, steep fiords, pristine lakes, raging rivers, scenic beaches, and steaming volcanoes.

The North and South Islands have everything you would expect for a fabulous Williams GeoAdventure!  The North Island has the active volcano at White Island; the geothermal areas around Rotorua that are of significance for the Maori people; the second largest historic volcanic eruption and pyroclastic flow at Lake Taupo; collecting marine fossils at Castlepoint; hiking the volcanoes of Tongariro National Park, and viewing the Wellington fault scarp.

The South Island has the majestic beauty of the Southern Alps at Milford Sound in Fiordland National Park; a Jurassic Age fossil forest on the South Coast; igneous, sedimentary, and metamorphic rocks dating back over 500 million years; gold mines and ghost towns from the 1860s; and the charming small cities of Christchurch, Dunedin, Invercargill, and Queenstown. Outstanding optional trips on the South Island include a Milford Sound cruise, Taieri Gorge train trip, and the Shotover Jetboat.

Itinerary for 2017 New Zealand Geology Field Trip
Contact Tom for details on the New Zealand Geology Field Trip


Dolo-Slovo Geology Field TripDolo-Slovo Rocks!
Summer 2018

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?

Draft Itinerary for the Dolo-Slovo Rocks! 2018 Trip
Contact Tom for more information and to be added to the Interested Parties list

U.S. trips


Grand Canyon Geology TripGrand Canyon Raft & Rock
Upper Grand Canyon: August 26–31, 2017
$2,115 Rafting Trip + $565 Williams GeoAdventures Services = $2,680, $300 off! Limited time!

Upper & Lower Grand Canyon: August 26–September 8, 2017
$3,830 Rafting Trip + $650 Williams GeoAdventures Services = $4,480

Registration Open

Photos from previous Grand Canyon trips

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 2017 Grand Canyon Raft & Rock Trip


Death Valley Geology TripGeology of Lassen Volcanic National Park
September 14–17, 2017 | $400

An extended weekend camping and geologic field study of Lassen Volcanic National Park, the most recently active Cascade volcano in California. Hike to the top of Brokoff Mountain, with views of six physiographic provinces. Explore the inner craters of Cinder Cone, a volcano that has erupted several times in the last few hundred years. Visit the hot springs at Bumpass Hell and Sulphur Works. Hike through a lava tube cave and witness the devastation of a volcanic mudflow from the 1913 eruption of Lassen. Discover how this volcanic region is related to movements of the North American and Pacific tectonic plates.
Details on the Geology of Lassen Volcanic National Park 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


Scotland Rocks!
June 2017 Photos

Geology of Death Valley National Park March 2017 Photos

California North Coast Geology Field Trip September 2016 Photos

Iceland Rocks! GeoAdventure July/August 2016

Scotland Rocks! II – The Islands of the West Geology Field Trip June 2016 Photos

Yosemite-Eastern Sierra Geology Field Trip September 2015

Scotland Rocks! Geology Field Trip June 2015

Italy Rocks! GeoAdventure June 2014 Photos

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