An intriguing cluster of rocks sits quietly on the counter at Maklin Bike Shop in Scandia, MN, begging the question. Lynn Hamlin, who owns the shop with her husband, Steve, has the answer.

“Chalcedony. Our sons collect rocks,” she says. “You’d be surprised how many people who are into biking are also into rocks.”

Okay, curiosity piqued. Fortunately, it’s a good time to catch up with brothers Kyle and Reid Hamlin to find out more. On Saturdays in mid-winter, these teens are often helping at the shop, doing tune-ups and repairs on bikes in for service. Any other time of year, Kyle (18), and Reid (16) would likely be found on their own bikes. These two are serious athletes: in 2025, Reid rode 6,600 miles on his bike and Kyle rode 7,000. Many of these miles were logged in races, one of which was a 240-mile race across the state of Minnesota. They also do a fair amount of mountain biking. Off-season, they’re on trainers.

Rock-hounding is also a serious—albeit slower-paced—pursuit for these brothers. Kyle thinks his first memories of being interested in rocks were when he was a first-grader, hunting for agates in their North Branch driveway. Reid soon followed suit.

In the years since, gravel roads near home have continued to offer good agate hunting. When the light is right, they can spot their translucent glow while walking and even while riding on their bikes (they’re careful). Family outings to Lake Superior beaches and Moose Lake, MN as well as vacations to outdoor sites across the country have also provided opportunities for exciting finds.

The world opened further when Kyle got his driver’s license and the two were able to head out on rock-inspired adventures of their own. “We took a 3-day trip last Thanksgiving to the Black Hills Rockhound Area in Arizona, which is on Bureau of Land Management (BLM) land,” says Kyle. They were tent-camping and hoping to find some of the fire agates for which the area is known. It took some doing, says Kyle, hiking back on trails farther away from the campground, looking for the dark rocks which are often covered in mud. “Usually, you’re finding smaller ones,“ says Kyle, “but now and then Boom!,” he laughs. “Yeah, we’d put them in our backpacks,” says Reid, “and carry them back to the campsite to rinse them off. That’s when you’d get a better idea of what you had.”

Reid pours his fire agates out of a bag onto the counter and sorts through them. He picks one and holds it up: “Here’s my best one: when you move it, it changes color.” He points out a glittering pocket of green: “See that? That’s what you’re going for.”

The website for the Black Hills Rockhound Area describes fire agate as having “the color play of a precious opal with gem quality reds, greens and blues.” According to the site, the fire agate was not identified and formally recognized until the 1930s. Worldwide, it is only known to occur in the desert regions of Arizona, southern California, and central Mexico, associated with volcanic deposits.

A big part of the appeal of rock-hounding for the brothers is spending time outdoors. Says Kyle, “It’s fun. In Arizona, there are views of the mountains, and the sunrises and sunsets are great. When it gets really dark the stars are beautiful. Around here, you get to be along rivers and on beaches by Lake Superior.” Reid nods and adds: “And it’s the adventure: sometimes you have to look farther and get into harder, more remote places, to find the good ones.” Plus, they both say, rocks are cool.

More recently, visits to relatives in Michigan’s UP (where mom Lynn grew up) have focused on hunting for “omars,” or Omarolluks, which are easier for their young cousins to spot than agates.

While the name may not be familiar, most of us who live in the Great Lakes Region have probably seen an omar. With their gray appearance, they can resemble fine-grained basalts which are igneous rocks. But omars are greywacke, sedimentary rocks made up of sands derived from basaltic rocks. Their most notable features are the holes in the rock. According to the Michigan Technical University’s Keeweenaw Geoheritage site, these spherical features are formed by the weathering of calcareous “concretions:” the relicts of cyanobacteria colonies that once occupied pore spaces in the sediment. When these concretions erode out of the greywacke, they leave behind the distinctive holes. Omars found along Superior’s shores in Michigan’s UP (and along Minnesota’s north shore) had their origins in the Omarolluk Formation of Hudson Bay and were transported roughly 700 miles by glacial ice.

The sampling of rocks that Kyle and Reid have brought in for our conversation represents only a small part of the collection they keep at home. How many do they think they have? Kyle doesn’t venture a guess. Reid checks a tally he keeps on his phone: “Well, my box here has about 2622 Lake Superior agates,” he says. We laugh at the “about.” Clearly, anyone thinking of slipping one of Reid’s agates into their pocket would be busted.

Petoskey stones, geodes, and petrified wood are on their radar for future trips. In National Parks, they know that rules against collecting apply. Says Lynn, “The boys will say, Mom, don’t even look down, because if you see something, you can’t take it home with you!”

Their rock-hounding is often a pretty solitary pursuit. That’s partly because they tend to go when it’s cold, after the biking season wraps up. But the Hamlin brothers do share some of their better finds on Instagram. Follow Reid at https://www.instagram.com/agate_cyclist and Kyle at https://www.instagram.com/interesting_rocks.

Are their friends interested in rocks too? They think about it, then look at each other and shake their heads, no.

“Well,” says Kyle, “not yet.”

Note: For a deep dive into the origins of Lake Superior agates, check out “Gems in the Rift, https://www.agatemag.com/2017/08/gems-in-the-rift/ in Agate’s archives. Please be mindful that collecting is not allowed on some north shore beaches within state Scientific & Natural Areas (SNAs). Thank you to Howard Mooers, Professor Emeritus, Earth and Environmental Sciences, University of MN Duluth, for input into this story. And special thanks to Lynn, Reid and Kyle Hamlin, who contributed their time and all the great photographs (except where noted). And you’re right; rocks are just cool.