Yellowstone National Park: Narrow Gauge
Link some of Yellowstone National Park's most striking thermal features on this 5.2-mile loop near Mammoth Hot Springs.
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Travel beyond Mammoth Hot Springs to discover some of Yellowstone’s more extraordinary thermal features, as well as classic views of Mount Everts, Bunsen Peak and the Gardner Canyon. Starting from the Mammoth Terrace Trail, turn right onto the Sepulcher Mountain Trail to head toward Hymen Terrace, a broad travertine formation backdropped by the stately Mount Everts.
Continuing to the west, pass through a grassy meadow frequented by grizzlies as the trail climbs upward at a moderate grade. After winding through woods dotted with Douglas firs and aspens, the trail flattens out around mile 2.1 and crosses into a broad, grassy field, offering superb panoramas of Mammoth Hot Springs, the surrounding mountains, and a pine-blanketed countryside.
From the grassy plateau, it’s an easy downhill to the Orange Spring Mound at mile 3.9. This 20-foot-high feature, which owes its signature orange hue to microbial bacteria, has grown so large that it actually hides the spring that feeds it. Less than a half mile further, the trail visits the Narrow Gauge Terrace where a set of terraced, travertine pools emit steam and vapors. Break out your camera to document this striking geothermal feature before heading back to Waypoint 4 and turning right to complete the loop.
MORE PARK INFO Yellowstone National Park, (307) 344-7381; nps.gov/yell/
-Mapped by Jeff Chow


























Trail Facts
- Distance: 8.4
Waypoints
NRG001
Location: 44.9730413, -110.7039768
Head north on the Mammoth Terraces Trail.
NRG002
Location: 44.9737395, -110.7042825
Turn left to head west toward Hymen Terrace on the Sepulcher Mountain Trail.
NRG003
Location: 44.973444, -110.705065
Pass Hymen Terrace, a low, steaming feature framed by Mount Everts in the background. Keep your eyes open for elk.
NRG004
Location: 44.9732538, -110.7083434
Bear right at Y-junction on the Sepulcher Mountain Trail; bypass the Howard Eaton Trail. Cross the bridge to continue your steady but moderate climb upward.
NGR005
Location: 44.9753562, -110.7138956
Turn left to stay on the Sepulcher Mountain Trail at the Y-junction. Caution: Grizzlies frequent this grassy area.
NGR006
Location: 44.974785, -110.723527
Cross a hillside bridge. The grade lessens here as the trail weaves through aspen groves and Douglas firs.
NGR007
Location: 44.973164, -110.727597
Veer left off the Sepulcher Mountain Trail onto the Clagett Butte Trail. Walk over a footbridge that crosses a small stream and begin a very brief descent.
NGR008
Location: 44.9712804, -110.7271135
Cut between a horseshoe-shaped pond on the left and a small green pond on the right as the trail begins swinging uphill again.
NGR009
Location: 44.966394, -110.726848
Pop out of the forest and into a flat sagebrush meadow that showcases spectacular views of Bunsen Peak (named for the guy who invented the Bunsen Burner), Gardner Canyon, Mammoth Hot Springs, Mount Everts.
NGR010
Location: 44.9639553, -110.7267809
Stay on the Claget Butte Trail at the Y-junction.
NGR011
Location: 44.96085, -110.728021
Turn left at the Y-junction to bypass the trail on the right leading to Snow Pass.
NGR012
Location: 44.9608618, -110.7189113
Flanked by juniper bushes, fir and moss, the trail passes by formations of travertine (a chemical precipitate of calcium bicarbonate that comprises the terraces). These sedimentary rocks suggest the presence of a hot spring in the area at one point.
NGR013
Location: 44.960388, -110.717038
To the right, pass a narrow, gaping cleft that plunges down 50 feet.
NGR014
Location: 44.959241, -110.7151079
At the Snow Pass Trail junction, hang an immediate left onto the unmarked trail.
NGR015
Location: 44.9666729, -110.7151401
Hit the Orange Spring mound, a 20-foot high, 30-foot long, calcium carbonate deposit. The mound’s several spring outlets cause the feature to transform at a rapid rate. Look for the dead stalks of suffocated trees, cemented into the mound’s rounded-out structure.
NGR016
Location: 44.969563, -110.7105669
Turn right at the Y-junction to hit Narrow Gauge Terrace, a highly active feature that has grown over six feet in the past three years. Surrounded by terraced hot pools and trees struggling to survive, the terrace emits smells of rotten eggs (actually sulfur).
NGR017
Location: 44.9695042, -110.7100815
After getting your fill of Narrow Gauge, head north to follow the trail back to Waypoint 4 and turn right to reach the trailhead.
Narrow Gauge Terrace
Location: 44.969514, -110.710378
Grizzly Bear
Location: 44.975238, -110.716105
Back-Scratching Grizzly
Location: 44.975307, -110.717332
Small Pond
Location: 44.9717965, -110.7274461
Bunsen Peak
Location: 44.96473, -110.726842
Jaw Bone
Location: 44.962539, -110.726641
Shells
Location: 44.961488, -110.727051
Wildflowers
Location: 44.961392, -110.727244
Narrow Gorge
Location: 44.9603797, -110.7168031
Meadow
Location: 44.961698, -110.715668
Orange Spring Mound
Location: 44.9644943, -110.7162237
Steam From Orange Spring Mound
Location: 44.9667849, -110.7150757
Front View of Orange Spring Mound
Location: 44.966726, -110.7151133
Orange Spring Mound Profile
Location: 44.967191, -110.7144454
Orange Spring Mound Close-Up
Location: 44.9672175, -110.7143998
Orange Spring Mound Texture
Location: 44.9672479, -110.7143542
Round Pools at Narrow Gauge Terrace
Location: 44.968249, -110.711821
Dead Trees at Narrow Gauge Terrace
Location: 44.969432, -110.710684
Steaming Pools at Narrow Gauge Terrace
Location: 44.969441, -110.710549
More Views: Narrow Gauge Terrace
Location: 44.969441, -110.710549
Submerged Trees: Narrow Gauge Terrace
Location: 44.969441, -110.710549
Steaming Falls at Narrow Gauge Terrace
Location: 44.969356, -110.710501
Sunset at Narrow Gauge Terrace
Location: 44.969514, -110.710378
Lone Tree at Narrow Gauge Terrace
Location: 44.96957, -110.710143
Narrow Gauge Terrace Sign
Location: 44.969342, -110.710525
Overlook
Location: 44.970155, -110.709885