The traditional territory of the Semá:th people (Sumas First Nation), a band of the Sto:lo Nation,[3] the lake lay midway between the present-day Canadian cities of Chilliwack and Abbotsford, British Columbia, and extended past the Canada–United States border into the territory east of Sumas, Whatcom County, Washington, necessitating a British Columbia Electric Railway trestle (which remains today as a dyke) across it from Huntingdon to the foot of Vedder Mountain.

The lake used to support sturgeon, trout, salmon, grizzly bears and geese, and its wetland habitat was a destination for migrating birds and a breeding ground for both fish and waterfowl.

[3][4][5][6] In the late 1800s, the lake drew the attention of various naturalists within the growing European population engaged in the work of cataloging the flora and fauna that they encountered where they settled.

[10] After the devastating 1894 Fraser basin flood, and in order to create more fertile farmland for settlers, BC Electric engineer Fred Sinclair formed a plan to drain the lake in the early 1920s.

[24][1][25] Following the long history of repeated flooding and the particular calamity of Fall 2021, there has been discussion[26][27] including among experts about appropriate ongoing management of the former Sumas Lake area, taking into consideration circumstances of climate change, food security, social justice in relation to the colonial history of dispossession, and the relative costs of attempting to maintain the status quo compared to managed retreat.