The Richardson and Denali Highways to Mount McKinley National Park, 1966

"Black Rapids Glacier
The Galloping Glacier
    Like an icy tidal wave, this mile-wide column of ice moved to within one-half mile of the Richardson Highway during the height of its stage of advance in the winter of 1936. During this six months of great activity, the galloping glacier, 200 to 300 feet high, advanced a distance of four miles, giving an average daily advance of 115 feet. In February 1937, the surging Black Rapids Glacier hit its maximum advance and began an energetic retreat. The glacier is still receding."