Matanuska Glacier is a valley glacier in the US state of Alaska. At 27 miles (43 km) long by 4 miles (6.4 km) wide, it is the largest glacier accessible by car in the United States. Its terminus is the source of the Matanuska River. It lies near the Glenn Highway about 100 miles (160 km) northeast of Anchorage. Matanuska Glacier flows about 1 foot (30 cm) per day. Due to ablation of the lower glacier, as of 2007, the location of the glacier terminus changed little over the previous three decades. The glacier is the eponym of the Alaska Marine Highway ferry M/V Matanuska.