Tatanka Trailhead to Reva Gap — Cave Hills Badlands Rim Road via Slim Buttes
Lakota battlefield country, cattle, and nobody else.
Slim Buttes is where General Crook’s cavalry burned a Lakota village in September 1876 — a brutal postscript to the Little Bighorn campaign — and the land hasn’t forgotten. The Cave Hills unit of the Grand River National Grassland in northwestern South Dakota offers a raw, mostly ungated dirt road system running from the Tatanka Trailhead south through the ponderosa-studded buttes toward Reva Gap, where the escarpment drops back to the plains. The route passes genuine badlands formations, isolated buttes with cave sandstone overhangs, and some of the loneliest ranch country in the lower 48. You’ll share the road with cattle and almost no one else.
Difficulty is moderate when dry — hardpacked two-track with some rutted clay sections that turn genuinely greasy after rain. High-clearance 2WD can manage it in dry conditions; bring 4WD for anything after precipitation. No fee, no permit. Nearest fuel is Reva or Buffalo, South Dakota, both small and not always well-stocked — top off in Mobridge or Lemmon before you roll in. Best season is May through June and September through October; summer thunderstorms can shut the clay roads down fast. Water is non-existent on route — carry everything you need. Dispersed camping is permitted on National Grassland.
Trail Specs
| Difficulty | Moderate |
|---|---|
| Trail Type | Backcountry, Overland Route |
| Surface | Dirt, Gravel |
| Features | Camping, Historic, Remote, Scenic |
| Length (miles) | 34 mi / 54.7 km |
| Duration | 1-2 days |
| Max elevation (ft) | 3340 ft |
| Best season | May-June, September-October |
| Minimum vehicle | High-clearance recommended |
| Nearest town | Reva, SD |
| Land manager | USDA Forest Service — Grand River and Cedar River National Grasslands |
| Permit required | No |
| Cell service | None |
| Water crossings | No |
| Dispersed camping | Yes |
| Official sources | fs.usda.gov |
| Start coordinates | |
| End coordinates | |
| Copy both for Google Maps directionsClick to copy the directions URL · or open it directly in a new tab | |
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Location
Trail Conditions
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Frequently asked questions
Do I need a lifted rig, or can a stock high-clearance SUV handle this?
A stock 4Runner, Tacoma, or similar high-clearance SUV does fine under normal conditions. The dirt and gravel surface gets rutted and soft after rain, so lockers or A/T tires help but aren't mandatory for dry runs.
When is this route actually passable — and when should I stay away?
May–June and September–October are the sweet spots. Summer thunderstorms can turn the gumbo clay sections into an absolute mess overnight, and winter brings snow and ice with zero services nearby. Check local weather hard before you go.
Do I need a permit to run this route or camp out here?
No permit required. This runs through Grand River and Cedar River National Grasslands managed by the USDA Forest Service, so dispersed camping is allowed without a fee — just follow Leave No Trace and don't camp in active grazing allotments.
What's the hardest section and what am I actually dealing with?
The rim road stretch along the Cave Hills badlands edge is where things get honest — narrow shelf road, loose gravel, and exposure on one side with no guardrails. It's not technical rock crawling, but it punishes distracted drivers and demands attention.
There's no cell service out here — how far is the nearest gas and how should I plan for water?
Reva, SD is the closest fuel stop and it's tiny — confirm it's open before you leave, don't count on it. Carry all your water; there are no reliable potable sources on route, and the stock ponds you'll pass are cattle-shared and untreated.
Trail track
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