Despite their wider anonymity, the Iliamna seals have long been known to the Dena'ina Athabascan and Central Yupik peoples of southwestern Alaska, who have deep cultural and dietary ties to this small pinniped. Unlike other freshwater seal populations globally, the seals in Alaska's largest lake have been largely overlooked by scientists. Their remote location and the difficulties in studying these elusive animals have contributed to this lack of attention. It wasn't until 2013 that genetic research finally identified them as harbor seals.

A long-standing question has been whether the seals in Iliamna Lake were separate from those in Bristol Bay, the nearest marine population. The bay is connected to the lake by the 110 kilometer-long Kvichak River. Harbor seals commonly move more than 200 kilometers, and the relatively short distance between the lake and Bristol Bay, combined with sporadic sightings of seals in the river has led to the hypothesis that they move regularly between the freshwater and marine habitats.

A team of scientists, led by Florida Atlantic University, in partnership with local indigenous communities set out to find the answer. Researchers conducted a genetic study of seals in the lake and compared them to seals not only in Bristol Bay, but across almost the entire Pacific Ocean range of the species, from Japan to California.