Supply Trail

Supply Trail is a 4.6-mile out-and-back from its roadside access off Hosmer Grove Access Road to the Halemauʻu Trail junction. The National Park Service maps the trail corridor at about 2.3 miles one way and reports 975 feet of elevation change for the full return walk. Expect a mostly gradual climb through native high-elevation shrubland, then the same route back. Allow about 2½ to 3 hours; it’s a steady outing, not a quick loop.

The route starts on a short service road that narrows into a rocky path. The climb continues for most of the way, with several stream crossings and a crossing of the service road that serves the rain catchment. The footing is uneven, so the gradual grade can still ask for your attention. You return downhill on the same corridor.

The large rain catchment sits just off the trail and begins to come into view around 1.3 miles. It’s a useful checkpoint on the climb and on the way back. The surrounding shrubland can look similar when cloud settles in; keep following the marked tread instead of cutting across the fragile plants.

This is a chance to see the summit area beyond the crater’s cinder slopes: low native shrubs, ʻŌhiʻa lehua and māmane, with nohoanu among the flowering plants. The National Park Service notes that this shrubland supports plants important to nēnē and other endangered species. When ʻŌhiʻa crowns are in flower, native birds may be feeding in the trees; take a minute to look before you move on.

The Supply Trail ends at the Halemauʻu junction, which is the distance stored here. A route account places Halemauʻu Overlook about 0.2 mile farther along Halemauʻu Trail. Going there and back to the junction adds roughly 0.4 mile before you return on Supply Trail; it’s a worthwhile add-on if you want a crater view, but it’s a different endpoint from the base hike.

The Supply Trail access is on Hosmer Grove Access Road, just past the entrance station on the first road to the left. Parking there is described as limited, and the NPS map does not mark the exact pullout, so confirm the signed access before you leave the car. This is not the separate Hosmer Grove Loop. Stay on marked trails, keep hiking groups to 12 or fewer, and leave pets behind; pack animals are permitted on Supply Trail. There’s no food, gas or supplies available in the park.