Deer Mountain is a 3,001.97 feet mountain peak located in the Tongass National Forest in the Ketchikan Gateway Borough, Alaska, which dominates the skyline behind downtown Ketchikan. The Deer Mountain National Recreation Trail provides a strenuous hiking route to the summit, passing through temperate rainforests, muskeg and alpine meadows …Deer Mountain is a 3,001.97 feet mountain peak located in the Tongass National Forest in the Ketchikan Gateway Borough, Alaska, which dominates the skyline behind downtown Ketchikan. The Deer Mountain National Recreation Trail provides a strenuous hiking route to the summit, passing through temperate rainforests, muskeg and alpine meadows as it gains 2,600 feet of elevation over 2.75 miles from the trailhead in Ketchikan to the peak.