Type “South Dakota Wyoming border towns” into a search bar and you mostly get legal history about how state lines got surveyed, or a Wikipedia stub on a town of seven people. Nobody’s actually named the towns and told you why you’d care. So here they are, both sides of the line, laid out the way you’d actually hit them if you were driving the Black Hills loop.
Table of Contents
- TLDR: The Towns
- The Wyoming Side
- The South Dakota Side
- How Far Apart They Actually Are
- Which Ones Are Worth a Stop
TLDR: The Towns
On the Wyoming side, closest to the line: Aladdin, Beulah, Moorcroft, Sundance, and Newcastle. On the South Dakota side: Belle Fourche, Spearfish, Dewey, and Custer. Belle Fourche and Aladdin are the closest true border pair — about 30 miles apart on back roads. If you’re running I-90, you’ll cross the line between Beulah, WY and Spearfish, SD without much ceremony beyond a “Welcome to South Dakota” sign and a sudden urge to stop for fudge.
The Wyoming Side
Aladdin barely qualifies as a town — it’s a general store, a post office, and the remains of a coal tipple that once fed a mining operation now mostly forgotten except by rockhounds. The Aladdin General Store has been in continuous operation since 1896, which in a region where towns regularly vanish is its own kind of achievement.
Beulah sits right against the state line, close enough that the Belle Fourche River crosses back and forth between the two states more than once before it commits to a direction. It’s not a destination so much as a marker: this is where Wyoming stops being Wyoming.
Moorcroft is the junction town — I-90 meets US-14 here, and it’s the last real fuel-and-food stop before Devils Tower if you’re coming from the east. Ranching runs the local economy, and it shows: cattle trucks outnumber tourists most of the year.
Sundance owes its name to Sundance Mountain, and the mountain in turn gave Harry Longabaugh his outlaw nickname after he served eighteen months in the Crook County jail here for horse theft. The jail building still stands. That’s a better story than most towns this size get to tell.
Newcastle is the biggest of the Wyoming border towns and the one with actual infrastructure — grocery stores, a hospital, a golf course. It grew up around coal and later oil, and it’s the practical base camp if you want real amenities before heading into the more remote stretches of the Black Hills.
The South Dakota Side
Belle Fourche claims the geographic center of the United States, including Alaska and Hawaii — a designation the U.S. Geological Survey confirmed after the 1959 statehood additions shifted the math. There’s a monument downtown and a seasonal visitor center built around it, which makes this the rare border town with an actual landmark instead of just a highway exit.
Spearfish holds a genuinely wild weather record: on January 22, 1943, a Chinook wind pushed the temperature from -4°F to 45°F in two minutes flat, the fastest temperature swing ever recorded in the United States according to NOAA’s historical weather records. Spearfish Canyon, just south of town, is the better reason to visit today — a scenic byway cut through limestone walls that Kevin Costner filmed in for “Dances with Wolves.”
Dewey has a population of seven. That’s not a rounding error or an outdated census figure — it’s the actual number, making it one of the smallest incorporated towns in South Dakota. There’s a cemetery, a scattering of houses, and not much else, which is exactly the appeal if you collect tiny-town trivia.
Custer sits further south and carries more weight than its size suggests — it was the first white settlement in the Black Hills, founded during the 1874 gold rush that Custer’s own expedition helped trigger. Today it’s the gateway to Custer State Park, home to one of the largest publicly-owned bison herds in the country, managed by the National Park Service’s regional partners alongside the adjacent Wind Cave National Park.
How Far Apart They Actually Are
If you’re plotting a route rather than just collecting names, here’s what the drive looks like:
- Belle Fourche, SD to Aladdin, WY: about 30 miles on county roads — the shortest true border-to-border hop.
- Newcastle, WY to Custer, SD: roughly 65 miles via US-16, cutting straight through Black Hills National Forest.
- Sundance, WY to Spearfish, SD: about 30 miles on I-90, the fastest of the interstate crossings.
- Moorcroft, WY to Belle Fourche, SD: around 45 miles, mostly flat ranchland before the terrain starts climbing into the hills.
None of these are long hauls. The whole cluster of towns fits inside a two-hour driving radius, which is part of why this makes sense as a single loop rather than a series of separate destinations.
Which Ones Are Worth a Stop
Not every town on this list earns a detour. Aladdin and Dewey are worth five minutes and a photo — you’re not building an itinerary around a general store and a cemetery. Beulah and Moorcroft are functional waypoints, useful for gas and food, not much else.
Sundance, Newcastle, Belle Fourche, Spearfish, and Custer are different. Each has something specific: an outlaw’s jail cell, real amenities, a geographic monument, a canyon drive, and a state park with actual bison. If you’re running the loop, that’s your five real stops, with the tiny towns as bonus trivia between them rather than the main event.
The border itself isn’t the attraction — it’s an invisible line through cattle country that happens to connect two states’ worth of Black Hills scenery. The towns sitting on top of it just happen to be a decent framework for seeing all of it in one trip.
