A shorter tributary glacier begins at the easternmost summit on the Mount Logan ridge at about 5,600 metres (18,400 ft) at about 60°35′0″N 140°22′40″W / 60.58333°N 140.37778°W / 60.58333; -140.37778.

All that summer, the new lake filled with runoff; its water level rose 25 metres (82 ft), and the decrease in salinity threatened its sea life.

In the next 24 hours, an estimated 5.3 cubic kilometres (1.3 cu mi) of water gushed through the gap, and the fjord was reconnected to the ocean at its previous level.

If this happens, the fjord could overflow its southern banks and drain through the Situk River instead, threatening trout habitat and a local airport.

On June 25, 2022, the cruise ship Norwegian Sun collided into a growler (a chunk of ice smaller than an iceberg) in foggy conditions as it approached the Hubbard Glacier for sightseeing.