One of the most popular places in Texas to find shark teeth is nearly four hundred miles from the sea. An hour’s drive north of Dallas is where Post Oak Creek lies just off an unremarkable stretch of road, south of downtown Sherman. A Google Maps pin labeled only “Shark Teeth” led me to the spot: the two-lane South Travis Street bridge, a few hundred yards east of U.S. Highway 75. Next to the bridge, an overgrown field beside an auto shop served as a makeshift parking lot. The place was strewn with trash. Styrofoam Whataburger cups and plastic grocery bags drifted in the breeze next to larger junk—twisted rebar, an old wooden pallet—and a row of broken-down cars. “Are you sure this is it?” my husband, Chris, asked as we loaded our one-year-old son into his carrier and then picked our way through the litter to the creek. The path down to the water was steep and rocky, so I was glad I’d worn hiking sandals. I concentrated closely on my steps, trying not to slip, until we arrived at the water’s edge. When I did finally look up, I’d been transported to another world. A lush, green canopy of trees obscured the road overhead, and the sound of water burbling over the pebbly bottom drowned out any traffic. The stream was cool and clear, with no trash in sight.
On this unseasonably chilly Saturday morning in May, a few other families were already here. We were all looking for shark teeth from about a hundred million years ago, when most of Texas was covered by a shallow sea. “I got one!” a little girl exclaimed, splashing through the knee-deep water to show off a shiny discovery.
I’d found this under-the-radar location via Google, which led me to several parenting blogs. One writer cheerfully described a trip to Post Oak Creek as “probably our most random adventure to date!” I was impressed by the photos of ancient fangs—some as long as a couple of inches—in shades of shiny brown, gray, and black. Another blogger bragged of finding 85 fossils in two and a half hours.
Word is starting to get out about this special place, and the city of Sherman’s plans to turn it into a public park will likely raise its profile further. About half a mile east of where we accessed the creek, a paved parking lot and safer steps leading down to the water are planned. The project is still in the design phase, with no timeline for construction.
One family we met said they’d heard about it from their kid’s elementary school science teacher, and another had driven out on the recommendation of a friend. Everyone was drawn by the high probability of taking home a handful of treasures. That’s not always the case with fossil hunting—or rockhounding, as it’s sometimes called—which is a lot like fishing: both depend heavily on luck.
Ready to try ours, we sat cross-legged on the bank and unpacked the homemade sieve Chris had built earlier that week. It was a simple ten-by-ten-inch grid, with wire mesh nailed to four pieces of wood. Tutorials are available online, but a flour sifter or kitchen colander would suffice as well. Then we got to work, using a garden spade to scoop pebbles into the sieve, which we shook to make the water, mud, and smaller debris fall away.
Playing with dirt and rocks is second nature to a toddler, so our son quickly set to “helping,” picking up pebbles one by one and dropping them into the sieve. (We did have to be vigilant to make sure none went in his mouth.) The routine was calming, even meditative: scoop pebbles in, shake the sieve, sift through by hand, dump it all out, repeat. After about twenty minutes of this, without seeing a single fossil, we decided to walk a few hundred feet upstream and try a different location.
We were in luck. You know a shark tooth when you see it, and I was delighted to notice one that was about an inch and a half long, dark gray with finely serrated edges, lying out in the open on the riverbank. The finds came quickly after that, tumbling into our palms: teeth in various shades of gray and black, from tiny centimeter-long specimens to fearsome chompers, plus other fossils that looked like clams, oysters, and pieces of prehistoric coral. After an hour and a half, we left with a baggie filled with twenty or so finds.
Texas law generally allows fossil collecting in public creeks and streams, but some digs require permits, and laws prohibit collecting certain artifacts such as arrowheads and stone tools from public streams. Rock hounds should also note that you cannot take fossils from state and national parks.
Back at home, we laid out our trophies on the kitchen table and marveled at them. We’d sifted for shark teeth once before, on vacation in Florida, but somehow it felt cooler to have collected them in our home state, far from any ocean. It’s mind-boggling to hold in your hand a tooth from around one hundred million years ago and imagine a world that looked utterly different.
During the Cretaceous period, most of Texas was submerged by a warm, shallow sea called the Western Interior Seaway. Pterosaurs swooped overhead, menacing crocodilians paddled through the mud, and fierce sharks with Pokémon-like names (Galagadon, Squalicorax) sent schools of fish fleeing in terror. The vastness of the sharks’ territory is hard to grasp. “The seaway went up through Texas and connected at some point to the Arctic Circle,” says Dale Winkler, research professor and director of the Shuler Museum of Paleontology, at Southern Methodist University. “Most of this area was flooded for at least forty million years.” These teeth survived for tens of millions of years for a few reasons, he explains. One is that sharks grow and shed a staggering number of teeth—in some cases, more than twenty thousand in a lifetime. Another is that “teeth are durable, and they’re small enough that they don’t get broken up easily.”
North Texas is known by hobbyists as a fossil hunter’s paradise. This stretch of Post Oak Creek isn’t geologically unique; rock hounds can turn up shark fossils in numerous nearby waterways. Did more ancient sharks swim across this region than elsewhere, I wanted to know, or do the geology and access here just make their remains more visible? Is it possible that back here, in Austin, I’m also sitting on top of thousands of prehistoric shark teeth?
“You definitely are,” Winkler says. “There are sharks’ teeth all around the Cretaceous of Texas”—a wide band that runs across a sizable portion of the state, including most of North and Central Texas, plus swaths of the southern and western reaches. In other words, these gems from the past are everywhere. You just have to know where to look.
Other Fossil Hot Spots
Where to find sea lilies, ammonites, and more.
Crystal Beach, Bolivar Peninsula
Should you prefer to combine your fossil hunting with a seaside vacation, this 27-mile-long peninsula east of Galveston is a phenomenal choice. Folks seem to have the best luck on Crystal Beach. You can drive right on the sand, though you’ll have to buy a $10 permit. As with any type of beachcombing, the best time to go is after a storm, when big waves will have churned up all kinds of treasures.
Mineral Wells Fossil Park, Palo Pinto County
Flowerlike sea lilies, spiky urchins, and oblong trilobites are a few of the marvelous finds you might come across at Mineral Wells Fossil Park, an eroded pit about an hour west of Fort Worth that now welcomes rock hounds. Admission is free, and you can take home whatever you uncover. There’s very little shade here, so bring sunscreen, a hat, and lots of water.
North Sulphur River, near Ladonia
Spiral ammonites the size of cinnamon buns are among the prized finds at this spot, about eighty miles northeast of Dallas. Or you might see a “devil’s toenail” oyster, which, yes, resembles a nasty, gnarled, overgrown nail.
This article originally appeared in the September 2023 issue of Texas Monthly with the headline “In Sherman, It’s Always Shark Week.” Subscribe today.