Northern Rockies sand and shelf road: St. Anthony, Killpecker, Alpine Loop

The Rocky Mountain region is not only alpine rock. Idaho and Wyoming each have an enormous dune field that is at its best in the summer months when the desert dunes further south are too hot to use, and the Colorado passes have just opened. This weekend pairs the two big northern sand areas with the Alpine Loop for a group that wants variety over a long weekend.

St. Anthony Sand Dunes in Idaho, managed by the BLM Upper Snake Field Office, is open riding across roughly 11,000 acres of dune, rated a 3. Difficulty is about sand skill rather than obstacles. An Idaho OHV sticker is required and non-residents need a non-resident certificate. The season is spring through autumn, with winter access limited by snow on the approach. Confirm with the managing agency before you go.

Summer dunes are cooler at St. Anthony than in the desert, but they are still sand: bring a whip flag, air down to the figure in your service manual, and stay off the crests until you have seen what is on the other side. The dunes are big enough to get lost in, and the open riding area has boundaries that are easy to cross without noticing. Carry a map of the area and know where the staging area is from any high point.

Killpecker Sand Dunes in Wyoming, managed by the BLM Rock Springs Field Office, is one of the largest active dune fields in North America. It is an open play area rated a 3, with desert two-track on the approach. No fee is generally charged, though Wyoming ORV permits typically apply and riding is limited to the designated open area. The season is late spring through autumn. Confirm with the managing agency before you go.

The approach roads at Killpecker are the thing to plan for. They are poor in wet or snowy conditions and remote in every condition, so a full tank, a spare tire for the tow vehicle and enough water for a stranded night are not overkill. Once on the sand, the same rules as St. Anthony apply, and the designated boundary matters even more because the surrounding land is closed to riding.

The Alpine Loop Backcountry Byway, managed by the BLM Gunnison Field Office, opens roughly late June and closes in September when the passes snow shut. Engineer and Cinnamon passes are moderate shelf road, rated a 5, with rock and creek crossings; side routes like Poughkeepsie Gulch are much harder. No permit is generally required, but Colorado OHV registration or a non-resident permit typically applies to unlicensed vehicles. Confirm with the managing agency before you go.

In mid-July the Alpine Loop still carries snow in the shaded sections and the creek crossings run high with melt. That makes it a very different trail from the same route in September. Walk any crossing you are unsure of, and expect lingering drifts on the north sides of the passes. Afternoon storms build fast above treeline, so plan to be over the passes by early afternoon.

Sand and shelf road ask different things of a machine. Sand is brutal on air filters and belts; check the filter after every dune day and inspect the belt before the alpine leg. Shelf road is about brakes and steering; look at pads and fluid, and check the steering joints, before you commit to a long descent. All of the torque values and capacities involved are in your service manual.

A last practical note. If the group is towing between these three, the distances are long and fuel is thin in between. Plan the fuel stops before you leave rather than on the road, and give the trailer tie-downs a second look at every stop.