It sits in a long, heavily glaciated valley, and abuts the calving face of Portage Glacier at its southern end.

The lake has only become visible since approximately 1914, with the rapid retreat of Portage Glacier.

(The Center was named after Congressmen Nick Begich and Hale Boggs, who were killed in a 1972 plane crash.

[4] Recreational boating in the lake was illegal in the past, due to rolling icebergs and the calving face of Portage Glacier at the far end of the lake, but is now legal, though proper precautions must be taken for the challenging conditions.

Its low temperature year-round makes Portage Lake a potentially dangerous locale for swimming or other water activities.