Dun Brook Mountain is a peak in New York’s Adirondack Mountains, in the town of Indian Lake east-northeast of Blue Mountain Lake, with Tirrell Mountain and Tirrell Pond nearby to the west. It held a small place in the Adirondacks’ early fire observation system when the Conservation Commission built a wooden tower on its summit in May 1911. Fire watching there was short-lived and ended in 1920. Since then, Dun Brook Mountain has been known chiefly as part of the Adirondack landscape rather than as an active fire tower location.