Ammo South Gully

Ammo South Gully is one of the ski lines in Ammonoosuc Ravine on the west side of Mount Washington, accessed from the Ammonoosuc Ravine Trail out of the USFS trailhead on Base Station Road. From the lot, follow the Ammonoosuc Ravine Trail toward Gem Pool and continue up until you can safely drop off the hiking trail and skin or boot into the obvious south ( skier’s left) branch of the main slide path.

The line is a confined avalanche gully with ice bulges, rock slabs and short cliff bands breaking up the snow surface. Expect a mix of firm bed surface, pockets of wind slab and thin snow over rock, with a pronounced terrain trap where debris runs into lower-angled catchments and against rock walls. Overhead hazard from ice and rock is real, especially during warm-ups or rain events.

Ammo South Gully is generally a winter and early-spring objective when coverage is continuous and the riverbed is bridged; in lean conditions the approach and exit involve thin snow over running water and awkward sidehilling. The gully faces roughly WNW and is heavily affected by wind loading from southerly and westerly storms, so slab distribution changes quickly—treat it as a serious avalanche path, not a mellow slide.

Check the daily avalanche forecast from the Mount Washington Avalanche Center before committing to the line, and be prepared to turn around if you see recent debris, cracking, hollow wind slab or exposed ice. Strong route-finding on the approach and exit is important to avoid open water and thin snow over boulders in the ravine floor. For current snowpack and closure information, see Mount Washington Avalanche Center.