Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Boulder Glacier is located in the U.S. state of Montana in Glacier National Park (U.S.). The glacier is situated to the north of Boulder Peak and west of the Continental Divide. Between 1966 and 2005, Boulder Glacier lost more than 75 percent of its surface area. As of 2005 the glacier was measured to cover only 13 acres (0.053 km2), and no longer met the 25 acres (0.10 km2) theshold often cited as the minimal area to qualify as an active glacier.