Overview
Gray's Arch is the crown jewel of the Red River Gorge arch system. The arch spans roughly 80 feet and rises approximately 50 feet from the hollow floor, forming a massive curved cathedral of gray sandstone that dwarfs visitors standing beneath it. The approach from the Koomer Ridge trailhead in Daniel Boone National Forest winds through one of the quieter hollows in the Gorge, following a small seasonal stream under a canopy of hemlock and rhododendron that stays green through winter.
The out-and-back route covers 4.2 miles and visits only the arch, but the Rough Trail junction near the arch opens loop possibilities for those wanting longer options.
The Route
Miles 0.0 to 0.8: Trailhead to Hollow Entry
The trail starts at the Koomer Ridge trailhead on KY-15 and initially follows a ridge before dropping into the hollow. The first portion crosses several other trail junctions; follow signs for Gray's Arch specifically. The descent into the hollow begins around mile 0.5.
Miles 0.8 to 1.8: Hollow to Arch Base
The path follows the hollow floor along a small stream, crossing it on stepping stones in two places. Rhododendron tunnels make this section particularly striking in winter when everything else is bare. The trail gains almost no elevation through the hollow bottom; what descent you've done stays with you until the return.
At mile 1.8 the arch comes into view through the trees. The final approach lifts slightly to reach the base of the arch from below.
Miles 1.8 to 2.1: Arch Exploration
A short spur leads directly beneath the arch, where the scale becomes apparent. The ceiling of the arch rises to about 50 feet at its highest point. The ground beneath is sandy and open. Many visitors spend 20 to 40 minutes here exploring different perspectives before returning.
Miles 2.1 to 4.2: Return
Return via the same route. The climb out of the hollow is gradual but sustained for about a mile.
When to Hike
April through May is excellent. Wildflowers bloom in the hollow, including trout lily, hepatica, and various trillium species. Spring seeps run freely.
June through August the hollow stays noticeably cooler than surrounding ridges due to cold air drainage. A summer visit here is more pleasant than most ridge hikes in the area.
October through early November provides fall color that frames the gray arch dramatically. This is the busiest period.
December through March offers solitude. The hollow's evergreen rhododendron and hemlock provide color when the rest of the forest is bare.
What to Bring
Many hikers carry 2 liters of water for this trip. The hollow streams are present but water should be filtered before drinking. Trekking poles help on the descent into and climb out of the hollow. Waterproof shoes or boots are useful if any stream crossings are running high after rain.
Trailhead Access
The Gray's Arch trailhead shares the Koomer Ridge complex on KY-15 in the Red River Gorge. No fee for day hiking (as of 2026). Vault toilets at the main parking area. Koomer Ridge Campground, about 0.5 miles by road, provides developed camping with reservation (as of 2026). Dispersed camping is allowed at suitable sites in the hollow with proper USFS setback requirements.
Nearby
Auxier Ridge Trail departs from a different trailhead but offers a contrasting ridge-top experience. Rock Bridge Trail is another arch-focused loop in a different part of the Gorge. Check current conditions before your visit at checking conditions before you go, and practice Leave No Trace principles throughout.