Roadside Geology Books: Every State, Newest Editions and Best Picks

Most popular in the series

1. Roadside Geology of Washington

Washington has active Cascade volcanoes, a subduction zone off the coast and the Channeled Scabland, the landscape cut by more than forty of the largest floods known on Earth at the end of the last ice age. Marli Miller and Darrel Cowan cover all of it along more than forty highways, from 45-million-year-old sandstone in the sea cliffs at Cape Flattery to 1.4-billion-year-old rock near Spokane.

It has more Amazon ratings than any other book in the series. Miller is also a geology photographer, and most of the photos in the book are hers.

• Marli B. Miller and Darrel S. Cowan
• 2nd edition, 2017, 392 pages, full color
• Best stretch: I-90 across the Channeled Scabland

Good: the ice age floods, the volcanoes and the coast in one book, with photos taken for it. Not great: the Oregon side of the Columbia River Gorge is in the Oregon book, so a Gorge trip needs both.

Best writing for a nongeologist

2. Roadside Geology of Oregon

The first edition came out in 1978, before geologists knew that Oregon’s Klamath and Blue Mountains are pieces of old island arcs and ocean floor that drifted in and stuck to North America. Marli Miller rewrote the book from scratch for the second edition, so the plate tectonics story runs through every chapter instead of being added at the end.

Oregon is a good state to learn the series on. In a single day of driving you can cross a volcanic arc, a basalt plateau and a desert basin with a fault on each side.

• Marli B. Miller
• 2nd edition, 2014, 400 pages, full color
• Covers the Cascades, the coast, the Columbia River basalts and the Basin and Range

Good: a complete rewrite, not a patch on a 1970s book. Not great: it is now more than ten years old, so a few landslides and eruptions since 2014 are missing.

Best for a national parks road trip

3. Roadside Geology of Utah

Arches, Canyonlands, Capitol Reef, Bryce Canyon and Zion sit on the Colorado Plateau, where the rock layers lie nearly flat and each canyon wall is a page of the same history. This book’s 65 road guides cover the interstates and the slow two-lane highways between the parks, plus the Wasatch Range and the Great Basin to the west.

Buy it for a Utah parks loop. The drives between the parks take longer than the hikes, and that is where this book is most useful.

• Felicie Williams, Lucy Chronic and Halka Chronic
• 2nd edition, 2014, 384 pages
• 65 road guides and more than 300 color photos, maps and figures

Good: 65 road guides, more than most state books. Not great: it covers the whole state briefly; for site-by-site detail in the southern parks, add Geology Underfoot in Southern Utah.

Best for mountain passes

4. Roadside Geology of Colorado

Colorado’s rocks come in white and red sandstone, green shale and pink granite, and the third edition was the first one printed in full color. It added the mastodons and other ice age fossils found at Snowmass and newer parks such as Chimney Rock National Monument.

The book is strongest on the passes, where a single road climbs from sedimentary layers on the plains up into granite more than a billion years old.

• Felicie Williams and Halka Chronic
• 3rd edition, 2014, 416 pages, full color
• Halka Chronic wrote the original Colorado, Utah and Arizona books

Good: clear maps of complicated mountain geology. Not great: for Denver to Boulder day trips, Geology Underfoot Along Colorado’s Front Range covers individual stops in more detail.

Best for Northern California

5. Roadside Geology of Northern and Central California

California needs two books. This one covers the northern two thirds of the state: the Sierra Nevada, the Coast Ranges, the Klamath Mountains and the Cascade volcanoes of Mount Shasta and Lassen Peak, plus the San Andreas Fault through the Bay Area.

David Alt and Donald Hyndman wrote several of the earliest books in the series, and this second edition is in full color.

• David Alt and Donald W. Hyndman
• 2nd edition, 2016, 384 pages
• Photographs by Katherine J. Baylor

Good: Yosemite, Tahoe, the Bay Area and the north coast in one book. Not great: Los Angeles and the southern deserts are in the separate southern book, so a full coast trip needs both.

Best for Southern California

6. Roadside Geology of Southern California

Southern California is where the San Andreas Fault runs closest to the most people, and the book follows it along with the Transverse Ranges, the Mojave Desert, Joshua Tree and the Salton Trough. Arthur Gibbs Sylvester is a structural geologist who taught at UC Santa Barbara and has studied the state’s faults for decades.

• Arthur Gibbs Sylvester and Elizabeth O’Black Gans
• 2016, 400 pages
• Pairs with the same authors’ Geology Underfoot in Southern California

Good: written by a fault specialist, which matters in this part of the state. Not great: desert routes are long, so read the next section before you reach it, not at the turnoff.

Best for empty highways

7. Roadside Geology of Nevada

Nevada is the Basin and Range at its plainest: the crust is being pulled apart, and the result is long mountain ranges with flat valleys between them, repeated across the state. The book covers more than thirty highways, including the shorelines of ice age lakes, the tufa towers at Pyramid Lake, the ichthyosaur fossils at Berlin and the Great Unconformity at Frenchman Mountain near Las Vegas.

On US 50, called the loneliest road in America, there is little to look at except geology. This book turns those hours into something to talk about.

• Frank DeCourten and Norma Biggar
• 2017, 416 pages
• Also covers mining history at Virginia City and the Comstock Lode

Good: it makes the dullest-looking state on the map worth reading about. Not great: no newer edition since 2017, and there is no Geology Underfoot book for Nevada to add detail.

Biggest book in the series

8. Roadside Geology of Montana

At 480 pages, the Montana second edition is the thickest book here. It covers the ripple marks up to 50 feet high left when Glacial Lake Missoula drained, the dinosaur badlands of the east, the copper mines of Butte and the north edge of the Yellowstone volcano.

The series started in Montana. Its first book, Roadside Geology of the Northern Rockies (1972), was later split, and the Montana part became this title.

• Donald W. Hyndman and Robert C. Thomas
• 2nd edition, 2020, 480 pages, full color
• Illustrated by Chelsea M. Feeney

Good: one of the newest full revisions, and very thorough. Not great: it is heavy for a glove box.

Newest edition, best for Grand Canyon trips

9. Roadside Geology of Arizona

Halka Chronic’s 1983 original was one of the most loved books in the series. The 2025 second edition by Stephen Reynolds and Julia Johnson replaces it with a full-color book covering the Painted Desert, the red and white sandstone of Sedona, Petrified Forest National Park and the copper districts of Bisbee and Morenci.

The Grand Canyon chapter explains the 1- to 2-billion-year-old rocks at the bottom of the canyon. Related rocks also crop out in parks on the edges of Phoenix, Tucson and Prescott, so the book works for day trips too.

• Stephen J. Reynolds and Julia K. Johnson
• 2nd edition, 2025, 432 pages, full color
• The first book GSA published after taking over the series

Good: the newest research in the series, written by longtime Arizona geologists. Not great: used listings still sell the 1983 edition, so check the cover says Second Edition.

Newest edition, best for Big Bend

10. Roadside Geology of Texas

Before September 2025 the Texas book had not been revised since 1991. The third edition covers 50 roads plus nearby parks, including five roads inside Big Bend National Park, with more than 250 color photos and illustrations.

Texas is a big state with long drives, and the geology changes more than most people expect: Gulf Coast barrier islands, Hill Country limestone, the Llano Uplift’s granite and the volcanic mountains of the Trans-Pecos.

• Paul Brandes and Darwin Spearing
• 3rd edition, 2025, 374 pages, full color
• ISBN 978-0-8137-4128-4 (the new GSA number)

Good: brand new, and the first full Texas update in more than thirty years. Not great: Amazon still lists the two older editions on separate pages; this button goes to the 2025 one.

Best for desert landforms

11. Roadside Geology of New Mexico

New Mexico has the gypsum dunes of White Sands, the limestone caverns of Carlsbad, the tent rocks of Kasha-Katuwe, lava tubes, cinder cones and dinosaur trackways. The 2024 second edition updates Lucy Chronic’s original with full-color maps and photos.

• Magdalena Sandoval Donahue and Lucy Chronic
• 2nd edition, 2024, 368 pages, full color
• Illustrated by Chelsea M. Feeney

Good: new, and well paired with a White Sands or Carlsbad trip. Not great: used listings still sell Lucy Chronic’s first edition, so check the cover says Second Edition.

Best for lava fields and flood country

12. Roadside Geology of Idaho

Southern Idaho is the track the Yellowstone hotspot left as North America moved over it: the Snake River Plain, Craters of the Moon, and lava flows that dammed river valleys. North of the plain are granite mountains, and the whole state carries marks of floods released when ice and sediment dams broke.

Three field geologists wrote this 2021 edition, and it is built for people who want to stop. It points to specific road cuts and outcrops where you can park and walk up to the rock.

• Paul Link, Shawn Willsey and Keegan Schmidt
• 2nd edition, 2021, 416 pages, full color
• Willsey also wrote Geology Underfoot in Southern Idaho

Good: recent, and specific about where to pull over. Not great: Yellowstone itself is in a separate book.

Best for a volcano trip

13. Roadside Geology of Hawaii

The 2022 second edition includes the 2018 eruption of Kīlauea, which reshaped the summit caldera and buried hundreds of homes in lower Puna. It covers every main island, from the eroded older islands such as Kauaʻi, with Waimea Canyon, to the active volcanoes of the Big Island.

• Rick Hazlett, Cheryl Gansecki and Steve Lundblad
• 2nd edition, 2022, 336 pages, full color
• Includes lava tubes, black sand beaches and Haleakalā on Maui

Good: covers the 2018 eruption, and every island in one book. Not great: Kīlauea has kept erupting since it went to press, so check the USGS Hawaiian Volcano Observatory before you go.

Best for Alaska, by road or by boat

14. Roadside Geology of Alaska

Denali is still rising, pushed up by the plate colliding with Alaska from the south. The same collision built the Gulf Coast mountains and their icefields and caused the magnitude 9.2 earthquake of 1964. Cathy Connor’s second edition covers the roads of Alaska and the adjoining parts of British Columbia and the Yukon.

It also has a section on “boatside geology”: the fjords of Southeast Alaska, the Bering Sea islands and the Tatshenshini River. That makes it the right book for an Inside Passage cruise as well as a drive.

• Cathy Connor
• 2nd edition, 2014, 328 pages
• Covers glaciers, permafrost and the Alaska Highway

Good: works from a car or a ship deck. Not great: glaciers have retreated since 2014, so some photos show more ice than you will see.

Best for Yellowstone and the Tetons area

15. Roadside Geology of Yellowstone Country

Yellowstone holds about a fifth of the world’s geysers among more than 10,000 hot springs, fumaroles, mud pots and geysers. The book’s 19 road guides cover the park and the country around it in Wyoming, Montana and Idaho, including the petrified trees of the Lamar Valley area and the glacially carved Beartooth Mountains.

• William J. Fritz and Robert C. Thomas
• 2nd edition, 2011, 328 pages, full color
• Covers parts of three states, so it sits next to the Wyoming, Montana and Idaho books

Good: a whole book on one region instead of a chapter in a state book. Not great: 2011 is old for a place this active, and Amazon often sells it through other sellers, so check the edition on the listing.

Best for a state without a Roadside Geology book

16. Michigan Rocks!

Michigan borders four of the five Great Lakes, and its shorelines expose rocks from 3.6-billion-year-old gneiss to modern river potholes. The book guides you to 56 sites, from Isle Royale and the Upper Peninsula to the Thumb, including Lake Superior agate beaches and Petoskey State Park, where you can look for the state stone.

• Paul Brandes
• 2023, 144 pages, full color
• 56 sites, each with directions and a short explanation

Good: fills the biggest gap in the series. Not great: it is a site guide, not a highway guide, so it does not narrate the drive between stops. Our list of minerals in Michigan covers what you can collect.

Best for a cross-country trip

17. 101 American Geo-Sites You’ve Gotta See

If your route crosses six states, buying six Roadside Geology books is a lot of paper. This book picks at least one site per state, from Devils Tower to the Reelfoot scarp in Tennessee, left by the 1811 and 1812 New Madrid earthquakes, and Avery Island in Louisiana, which sits on top of a column of salt miles deep.

• Albert B. Dickas
• 2012, 264 pages, full color
• Covers all 50 states

Good: one book for the whole country, and good for picking stops before you leave. Not great: one or two pages per site, so it does not explain the road between them.

Best Geology Underfoot book

18. Geology Underfoot in Death Valley and Eastern California

Thirty-three sites, each a chapter of its own: Badwater, Zabriskie Point, the Racetrack and its sliding stones, Ubehebe Crater, the Alabama Hills, the bristlecone pines and the Long Valley caldera near Mammoth. The second edition builds on notes by Robert Sharp, who taught field geology at Caltech for decades.

• Allen F. Glazner, Arthur Gibbs Sylvester and Robert P. Sharp
• 2nd edition, 2022, 328 pages, full color
• Includes sites along US 395, from the Alabama Hills to the Mono Craters

Good: more detail per stop than any Roadside Geology book. Not great: it covers sites, not whole highways.

The one tool to bring

19. Ade Advanced Optics 10x Triplet Loupe

Geologists carry a 10x hand lens because 10x is enough to see the separate crystals in granite, the rounded grains in sandstone and the tiny holes in basalt. A triplet lens is three glass elements bonded together, which keeps the image sharp to the edges instead of blurring and fringing with color like a single cheap lens.

This one has a 21 mm glass lens, folds into its own metal housing and comes with a leather case. Hold it close to your eye and bring the rock up to it, not the other way around.

• 10x magnification, 21 mm triplet glass lens
• Leather case with snap closure
• About 1.6 ounces

Good: real triplet optics in a pocket size. Not great: add a cord or lanyard, because a loose loupe gets left on a rock.

For places where collecting is allowed

20. Estwing 22 oz Rock Pick (E3-22P)

The blue-handled Estwing is the standard rock hammer in North American geology field camps. It is forged from one piece of steel, so the head cannot work loose, and it has a square face on one end and a pointed pick on the other for splitting rock along its layers.

Wear safety glasses whenever you hammer, and keep children back. Rock chips fly fast and sharp. Never hammer in a national park or on a road cut beside traffic.

• 22 oz head, pointed tip
• One-piece forged steel, shock reduction grip
• About 13 inches long

Good: the hammer most geologists own. Not great: unnecessary unless you plan to collect, and illegal to use in national parks.