campgrounds.fyiIndependent · federal campgrounds · no paid placements
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USFSCuster Gallatin National Forest · Montana

Reva Gap Campground

A campground with 8 sites located in the Slim Buttes Unit near the Castles National Natural Landmark, one of two on the Sioux Ranger District.
Sites0all reservable
Elev.3,281ft
Comf.May-Oct6 months
Max rigtents
Electricnonesites
From Billings6h43real road time
The honest read
Synthesized from
RIDB · Open-Meteo
OSM · OSRM
Updated 2026-05-27

At 3,281 ft, Reva Gap Campground has a 6-month comfortable window (May-Oct). Winter nights average around 18°F, so the shoulder seasons turn cold fast. Within about 4 miles: lake or river access.

The campground at a glance

01 · CHARACTER
QuietCoolRoomyShadeRV-fitReserv.

Reads strongest on cool nights and quiet. Softest on quiet.

Six axes, each scored relative to every other federal campground in the region: quiet (miles to a major road), cool (elevation), roomy (average site spacing), shade, RV-fit (longest rig), and how reservable it is. All six come from data, nothing hand-tuned.

When to go

02 · CLIMATE
JFMAMJJASOND
avg highavg lowfrost-freedriest · Jan
May-Oct
Comfortable window: nights stay above 35°F, days below 90°F.
88%
Of summer weekend-days are dry.
May 10
Last spring frost; first fall frost Oct 9.
62°F
Average July low. Bring a fleece.

Getting there

03 · ACCESS
01
Billings
348 mi
6h43
02
Bozeman
491 mi
9h07
03
Helena
588 mi
10h54
04
Missoula
694 mi
12h23
By drive time
Billings · 6h43Bozeman · 9h07Helena · 10h54Missoula · 12h23Camp

Routed road time (OSRM). Nearest major highway 0.4 mi away.

What's within four miles

05 · TRAILS · PEAKS · WATER

Trails & Peaks

Water & Access

Lake / river access
yes
To nearest major road
0.4 mi
Method

We synthesize public data layers: RIDB and Recreation.gov facility and site records, Open-Meteo climate normals, OpenStreetMap roads, trails, and water, OSRM drive times, and USGS elevation. We take no bookings, no ads, and no paid placements. Independence is the entire point.

Check availability on Recreation.gov →