Mesa Falls: The Waterfall Detour Worth Skipping Breakfast For

Some mornings at Idaho Sky RV Resort are made for a slow coffee on the patio. This one is not. Grab a thermos, throw a jacket in the truck, and point it north. About an hour up the road, the Henry’s Fork of the Snake River throws itself off a volcanic ledge, and there is no better time to see it than a crisp fall morning when the aspens are turning and the summer crowds have gone home.

Where are Mesa Falls, and how far are they from Rexburg?

Mesa Falls Idaho is a pair of waterfalls, Upper and Lower, on the Henry’s Fork inside the Caribou-Targhee National Forest. They sit along the Mesa Falls Scenic Byway between Ashton and Island Park, about 45 miles northeast of Rexburg. From Idaho Sky RV Resort, plan on roughly an hour of driving each way. Take US-20 north through St. Anthony to Ashton, then follow the signs for ID-47.

That drive is half the point. The byway runs just under 29 miles, climbing out of farm country, crossing the Warm River, and winding through pine and aspen before rejoining US-20 near Harriman State Park. In late September and early October, the color along this stretch is some of the best in eastern Idaho.

One important note for fall 2026

Upper Mesa Falls, the big one, is closed this season. The Forest Service shut down the entire Upper Mesa Falls Recreation Area on August 10, 2026 for road repairs and chip sealing, and the project is expected to continue into winter. That means the boardwalk, the historic Big Falls Inn visitor center, and the upper parking lot are all off-limits until the work is finished.

Lower Mesa Falls is still open, and it is still worth the trip. Put the upper falls on your list for next season. Consider this year’s visit a preview.

Lower Mesa Falls: what you’ll actually see

Lower Mesa Falls sits just under a mile south of the upper falls along the byway, about 14 miles from Ashton. Pull into the parking area next to Grandview Campground and follow the short paved path to the wooden observation platform. From here the river drops 65 feet over a 200-foot-wide ledge of volcanic rock into a narrow, tree-lined canyon. The platform sits about a quarter mile back from the falls, so the view is wide and elevated rather than up close, and interpretive signs cover the geology. It’s an easy stop for anyone who prefers a railing to a staircase, and there is no fee to park here. Bring binoculars if you have them. Ospreys, eagles, and peregrine falcons work this stretch of canyon.

Give yourself 20 to 30 minutes. Longer if the light is good.

Turn the detour into a full morning

Mesa Falls is the anchor, but the byway strings together a few other stops that fit neatly into a half-day loop back to the resort.

Warm River. About nine miles up ID-47 from Ashton, the byway crosses Warm River at a small campground and picnic area. Stop at the fish viewing spot just before the bridge and watch the big trout hold in the current. Fall fishing here is quiet and easy to reach from the road.

Island Park and Big Springs. Past Lower Mesa Falls, the byway continues north on Forest Road 294 to US-20. Turn north for Island Park, where the coffee, lunch, and fuel you skipped on the way out are waiting. Big Springs, one of the largest natural springs in the country, is a short side trip with a footbridge over water so clear you can watch the trout below.

Harriman State Park. On the way back south, Harriman sits about a mile below the byway junction on US-20. This former Union Pacific family ranch has flat walking trails, historic buildings, and some of the most famous fly-fishing water in the country on the Henry’s Fork. Entry is a small per-vehicle fee.

Then drop back down US-20 through Ashton to Rexburg. Total loop: three to four hours with stops, and you’re back at your site before the afternoon wind picks up.

Practical notes for RV travelers

• Leave the rig at Idaho Sky. The byway is paved and easy in a truck or car, but the pullouts and the Lower Mesa Falls parking area are better suited to smaller vehicles.
• Cell service fades once you leave Ashton. Download your map before you go.
• Mornings run cold up here in fall. Dress in layers and expect frost on the railings early.
• Stage 1 fire restrictions are currently in effect on the Caribou-Targhee. Check the forest’s alerts page before you head out, especially if you plan to picnic.
• The Forest Road 294 section of the byway closes to cars in winter. Once the snow comes, the route is snowmobile and ski only.