American Border Peak, Mountain summit in Mount Baker Wilderness, Washington, United States.

American Border Peak is a mountain in the North Cascades of Washington, just south of the Canada–United States border. It lies within the Mount Baker Wilderness of Mount Baker-Snoqualmie National Forest, near North Cascades National Park. Its steep local relief is notable, but the somewhat rotten rock makes it less appealing to climbers than nearby Slesse Mountain.

American Border Peak lies just south of the Canada–United States border, paired with Canadian Border Peak across a connecting col. The North Cascades around it took shape as terranes were added to the continent about 50 million years ago, and Pleistocene glaciation later scoured the valleys. Its steep local relief and partly rotten rock have long made it less sought after by climbers than nearby Slesse Mountain.

The name marks the international boundary: the peak sits just south of the Canada–United States border, facing its sister summit Canadian Border Peak across a connecting col. The two names are a cartographic pair, and the border line runs between them.

Access to the peak involves hiking routes in the surrounding area, and climbers should bring sturdy equipment for loose rock. Good preparation and familiarity with alpine climbing are important for a safe ascent.

American Border Peak has a sister summit, Canadian Border Peak, just north across the border, linked by a col. The two are often climbed together, though the rotten rock on American Border Peak makes it less appealing than nearby Slesse Mountain.