The Ptarmigan Tunnel was built in 1930 through the Ptarmigan Wall at an elevation of 7,200 feet (2,200 m) in Glacier National Park, near Many Glacier. The 250-foot (76 m) tunnel allows hikers to avoid a strenuous climb over very steep terrain between Many Glacier and the Belly River valley. Two opposing steel jackhammers drilling from either side of the tunnel and a series of ten-hole rounds of dynamite gradually broke through the mountain in less than three months. A wide area, originally for guide and tourist horses, extends from each portal with a masonry retaining wall. Natural rock lines the interior walls. Heavy iron doors were hung across the tunnel adits during the summer of 1975. They remain open from mid-July until October 1, weather permitting. The 250 feet (76 m) long tunnel is a unique man-made feature in Glacier. This trail tunnel embodies exceptional qualities of landscape architecture and engineering in a pedestrian-scaled tunnel, cut through a sheer mountain wall.