Hubbard Glacier Alaska., Bernard Spragg Photo

The longest source for Hubbard Glacier originates 122 kilometres (76 mi) from its snout and is located at about 61°00′N 140°09′W, approximately 8 kilometres (5 mi) west of Mount Walsh with an altitude around 11,000 feet (3,400 m). A shorter tributary glacier begins at the easternmost summit on the Mount Logan ridge at about 18,300 feet (5,600 m) at about 60°35′0″N 140°22′40″W..Before it reaches the sea, Hubbard is joined by the Valerie Glacier to the west, which, through forward surges of its own ice, has contributed to the advance of the ice flow that experts believe will eventually dam the Russell Fjord from Disenchantment Bay waters.