What are the Henrie Knolls?
A chain of cinder cones north of Duck Creek Village. The Henrie Knolls lava flow dammed Duck Creek and created Navajo Lake. Forest Service spur 42 climbs just over two miles to the top of the northernmost knoll.
Ride from the inn
Henrie Knolls & Lava Flat
Up a cinder cone for the Pink Cliffs on the horizon
At a glance
- Distance from the inn
- 22.4 miles, out and back, from our lot and back
- Time
- 3 to 4 hours at about 10 mph plus stops
- Difficulty
- Intermediate
- Elevation
- Roughly 8,240 to 8,730 ft on the routed line (about 2,100 ft of climbing); the knoll summit is about 9,250 ft, which the terrain data under-reads
- Surface mix
- 8.1 mi designated OHV trail, 14.2 mi open forest road, highway crossings only
- Trails used
- Trail 4 Tommy Creek Loop corridor, spur 42 Henrie Knolls (2-mile climb), forest roads through the lava field
Route map
Legend
Routes
- Forest Service 4x4 OHV route
- OHV route, 72 inches or less
- OHV only
- Open forest road
- Featured ride from the inn
- Groomed snowmobile trail (winter)
Trail markers
- Easy (green circle)
- Intermediate (blue square)
- Expert (black diamond)
One digit is a loop; two digits is a spur of that loop (52 branches off Loop 5).
Points
- Duck Creek Village Inn
- Fuel
- ATV and UTV rentals
- Destination or trailhead
- Viewpoint
- Campground or camp
The Henrie Knolls & Lava Flat route from the inn, traced from the official 2019 Markagunt OHV System map. Tap a marker for the trail number.
The ride
Henrie Knolls is a chain of cinder cones north of the village, and the lava that poured out of them is the reason Navajo Lake exists: the flow dammed Duck Creek, and the lake has been backing up behind it ever since. This ride goes to the top of the northernmost knoll. From our lot it heads north through the black lava field and Lava Flat, joins the Forest Service Trail 4 Tommy Creek Loop country, and finishes on spur 42 Henrie Knolls, a two-mile climb to the summit.
The photo at the top of this page is ours, taken on the way back down: the road drops off the knoll with the Pink Cliffs on the horizon, and on a clear day the view runs across the whole plateau. The climb is what makes it intermediate; the rest is forest road at a steady grade. Our routed line shows about 2,100 feet of total climbing between roughly 8,240 and 8,730 feet, but elevation data under-reads the knoll itself, which tops out near 9,250 feet, so expect the last two miles to be steeper than the profile suggests.
What you'll see
- The village routes north out of Duck Creek Village and the SR-14 crossing
- The lava field north of the village, black rock under ponderosa and aspen
- Lava Flat, a designated dispersed camping area in the flow
- The Trail 4 Tommy Creek Loop corridor and the turn for spur 42
- Spur 42 Henrie Knolls: the two-mile climb up the northernmost cinder cone
- The summit view and the descent with the Pink Cliffs on the horizon
How the ride goes
7 legs, 22.4 miles out and back. Every ride starts and ends in our parking lot.
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Leave the inn's lot
Pull out of our lot onto Movie Ranch Road and follow the village OHV routes (spurs 52 and 59). Village streets are 15 mph and transit only. This ride heads north rather than toward the lake.
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Cross SR-14
Where the route meets SR-14, cross. If your machine is not street legal you may only cross the highway: stop, yield to traffic, and cross at a right angle. Street-legal side-by-sides may ride SR-14 itself under Utah Code 41-6a-1509, but nothing on this ride needs it.
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North through the lava field to Lava Flat
Forest roads lead north out of the village through the lava field to Lava Flat, a little over a mile north of the inn as the crow flies. Expect washboard and cinders; the flow is rough underfoot but the roads are graded.
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Into the Tommy Creek Loop country
The route continues north and joins the Forest Service Trail 4 Tommy Creek Loop corridor, where spur 46 Mammoth Cave and spur 42 Henrie Knolls branch. Follow the markers with a 4 and watch for the 42.
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Spur 42: two miles up the knoll
Spur 42 Henrie Knolls climbs just over two miles to the top of the northernmost knoll. It is the steepest sustained grade on any of our featured rides; take it in low range and give the machine ahead of you room on the cinders.
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Summit, then the descent with the Pink Cliffs ahead
From the top the view takes in the plateau, and on the way down the road points you at the Pink Cliffs on the horizon. Descend slowly; loose cinders do not grip like dirt.
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Ride home the same way
Retrace the Tommy Creek corridor south past Lava Flat, recross SR-14 with the same stop-and-yield rule, and roll back through the village to our lot. 22.4 miles as ridden from the inn.
Elevation profile
Good to know
Best time: Late morning on a clear day for the longest view from the top; late September puts gold aspen in the lava field. Avoid the knoll in wind and lightning.
- Our elevation profile under-reads the knoll: SRTM terrain data smooths the cinder cone, and the published summit is about 9,250 feet. Plan for a real climb.
- Cinders are loose; brake early on the descent and keep speeds down on the flow.
- Monsoon season: from July into September, storms build over the plateau by early afternoon. Ride early, watch the western sky, and get off exposed rims when you hear thunder.
- Width limit: Forest Service Order 0407-22-15 caps MVUM-designated trails at 72 inches and 2,500 pounds through 2027, and a few trails are narrower. Check your machine against the MVUM before you commit to a spur.
- Fuel only in the village: Loose Wheels / Phillips 66 at 835 E Movie Ranch Road (daily 9 to 6, gas and diesel) is the only pump out here, and there is none on the trail.
- Dust and dry roads: give riders ahead of you room, slow for oncoming machines on blind corners, and expect washboard on the open forest roads.
- Season: MVUM seasonal roads open May 1 to November 30. Spring mud order 0407-26-03 (signed March 26, 2026, rescinded June 1, 2026) posted Duck Creek OHV Trails 1 and 5 between the Visitor Center and Uinta Flat Road closed when wet, and a mid-season repair closure ran July 13 to 23, 2026 (order 0407-26-11). Last checked September 2026; ask at the front desk or the Visitor Center for the current order.
- Mileage, elevation and the route line were traced from the official 2019 Forest Service map and routed by computer, not ridden with a GPS. Carry the current MVUM; it is the legal document, and it changes.
Rules in full, including permits, helmets and the highway crossing law, are on our rules and safety page. Rentals and packing are on rentals and tips.
Henrie Knolls & Lava Flat: questions we get
What guests ask at the front desk before they head out.
How hard is the climb?
It is the steepest sustained grade among our featured rides, on loose cinders, which is why we rate the ride intermediate. The rest of the route is graded forest road. Use low range and descend slowly.
Why does the elevation profile look lower than the summit?
The profile is built from SRTM terrain data, which smooths small steep features like a cinder cone, so the routed line tops out around 8,730 feet while published summit figures are about 9,250 feet. Trust the summit number for the climb.
Can I combine this with Mammoth Cave?
Yes. Spur 46 Mammoth Cave branches from the same Tommy Creek Loop corridor. Our Mammoth Cave and Tommy Creek Loop ride does both in a full day of about 44 miles.
September 2026
Why trust this ride plan
We ride these routes and send guests out on them all season. The route line, mileage and elevation were traced from the official 2019 Forest Service Markagunt OHV System map and routed by computer, not recorded with a GPS, so treat them as a plan, not a survey. Loop and spur names, mileages and closures come from the Forest Service pages below; the highway crossing rule from Utah Code. Closure orders change: carry the current MVUM and ask at the desk.
Stay Where the Ride Starts
Rooms and cabins at Duck Creek Village Inn, trailer parking in our lot, rentals across the street, and the trail a few minutes from the door.