Reid Glacier is an alpine glacier on Mount Hood’s west slope in Oregon, entirely within the Mount Hood Wilderness. Descending from about 9,800 feet to around 6,000 feet, it feeds the Sandy River and is known for heavily crevassed upper reaches. It is a remnant of the far larger ice masses left from the last ice age, bordered by Yokum Ridge to the north and the ridge above Zigzag Glacier to the south, with Illumination Rock and Leuthold Couloir nearby. In the modern era it has shrunk markedly, losing 35 percent of its surface area between 1907 and 2004 while its terminus retreated 1,607 feet.