My first Estwing rock hammer...

serves as scale for various rock specimens that found their way home with me from travels around the world. Geologists tend to have pretty interesting rock gardens as a general rule.

1- Planar-tabular crossbedded Dakota Sandstone (Mid-Cretaceous) from Colorado Front Range north of Fort Collins, Colorado.

2- Peridotite clast from an aa lava flow on Hualālai shield volcano on the island of Hawaii.

3- Dacitic breadcrust bomb from the crater at Mount Saint Helens, Washington.

4 & 5- Silurian greywacke and Old Red Sandstone (Devonian) from Siccar Point, Scotland, the site of Hutton’s Unconformity.

6- Fossil coral (Devonian) from the Bastille karst, northern British Colombia.

7- Rare shatter cone feature from the Beaverhead impact structure (Neoproterozoic) in western Montana.

Having driven both Zodiacs and Zambonis...

it is imperative that one continues training and honing their skills through time, so today I once again took the magnificent Zamboni out on the ice at the University Recreation Center. It was a terrific review on the operation of the boxy behemoth conducted by geology undergraduate student Silas. Informative and fun!

Silas backs the Zamboni out of the garage and onto the ice.

Yours truly behind the wheel, zooming along at 5 mph (8 kph)! Although I wanted to feel the wind in my hair, I wore the ball cap to keep my hair out of my eyes at this blistering speed.

Driver’s point-of-view over the long hood. It does take some real skill to command this three ton beast but it pirouettes on a dime.

But, honestly, Zodiac MilPro MK4s are way more fun to drive! Happy geologist and Zodiac captain examining turbidites at Gold Harbour, South Georgia, in 2018.

A geology field class at Gardner Cave...

in Crawford State Park, Washington where university students learn cave science and mapping techniques. A former colleague invited me back into service given my long experience and expertise in the subterranean environment, and which turned out to be a thoroughly enjoyable two day-long project with a dozen undergraduate students.

Students learning to survey the illuminated upper part of the cave through which guided commercial tours are offered using tape and compass techniques.

Students recording carbon dioxide concentration in the cavern atmosphere.

Jazzed students exploring the wild, deeper part of the cave in a steeply descending passage. Note the flowstone false floor spanning sediments of glacial origin that were washed into the cave during the Pleistocene, and now are presently eroding by water flowing into the cavern from the surface.

Closeup view of delicate crystalline rimstone on the floor of the cave. Field of view is about three feet (one meter) wide.

It's the one year anniversary...

of ordering the Bronco from the dealership in Moab and it just had its first oil change and tire rotation at around 5,000 miles (8,000 km). Big fun, both on and off road!

The custom-ordered Ford Bronco Badlands-Sasquatch with manual transmission arrived in Moab at the end of October and it’s been huge fun ever since, seen here parked below Adobe Mesa in April.

An ocean of rolling sandstone slickrock...

is to be enjoyed on the famous Slickrock Trail. Don’t let the seemingly flat expanse in the image below deceive you but I cranked slightly more than 2,000 feet (610 m) of vertical ascent on the 10 mile (~16 km) trail. I first rode this line in the early 1980s on the upswing of mountain biking and it hasn’t gotten any easier at three score and nine years in age.

GPS track from my Garmin watch, color reflects speed.

Breaking in the brand new Bronco...

on the Dome Plateau today. Please excuse the Bronco porn that follows but this is its first time off road since being assembled only 28 days ago in Michigan.

Expansive view towards the south from a high point along the trail.

So-called “Cave Spring” in the Entrada Sandstone escarpment, used historically by ranchers to provide water to stock.

Relict uranium miner’s cabin on Owl Draw Upland.

The new manual Ford Bronco Badlands/Sasquatch is an enormously capable machine that will open up more areas in the backcountry for exploration. What’s a retired geologist to do when not mountain biking or launching rockets?!

Normally dry stream crossings...

turned into rapidly flowing muddy torrents within minutes in response to the passing of an intense thunderstorm cell. My neighbor and I were enrolled in the Bronco Off-Roadeo driving clinic and were out on the Dome Plateau trail undergoing guided training. It was absolutely perfect conditions to demonstrate the vehicle’s capabilities and the Bronco powered right through the mud and easily ascended wet and slippery slickrock.

Owl Draw on the Dome Plateau, north of Dewey Bridge.

Why the off road training? I am about to take possession of the 2025 Bronco Badlands/Sasquatch next week in Moab that I had ordered in late June this year. I’m somewhat excited!

3 November 2025 UPDATE: The Bronco has landed in Moab and is being prepped by the dealer.

Flipped 1,000 miles...

on the new Trek Rail+8 on the singletrack in upper Castle Valley this afternoon. Perfect place to accomplish this milestone. It’s good to be back on Mars.

The view over the handlebars. Click to enbiggen.

UPDATE: This puts me at 72% of the distance of the Earth’s circumference at the equator (since September 2020)!

My 8th grade earth science teacher...

stoked my early interest in geology and, next to my parents, Ellis Underkoffler is clearly the most pivotal person in my early formative life. Here we are, now years later, at a regional meeting of the National Association of Geoscience Teachers, Ellis having invited me to deliver the keynote address at the conference highlighting my adventurous cave research in Central America. It was a fun reunion. Inspiring teachers are important!

The five year anniversary...

of me fracturing my femur and requiring a hip replacement passes with hardly a notice, other than it being memorialized on my calendar on this date. Since then I’ve biked more than two-thirds of the circumference of the Earth, so it seems to be working well.

Closing in on 17,000 miles...

(27,000 km) ridden on my collection of electric mountain bikes since September 2020! My riding style is becoming increasingly aggressive with growing experience and time on the trail, so I’m leveling up with a new enduro-style eMTB. But the acid test of this very capable bike awaits on the considerably more challenging trails around Moab, Utah this fall.

It still has the new bike smell: Trek Rail+ 8 Gen 5 eMTB at Fish Lake on its first ride. The sidewalls of the tubeless tires matches the terrain in Utah!

A long and windy pilgrimage...

to another remote petroglyph panel occurred yesterday, with seven good friends of Rory Tyler hiking eight miles with his remains, dispersing them at this site where he had his epiphany in rock art interpretation.

Longtime friend of Rory’s, BH explains some of the symbols and their interpretations at the panel.