[4] The freshwater of the Squamish River mixes with the saltwater of Howe Sound, resulting in a varied ecosystem containing different habitats that support an abundance of wildlife.

Threats to the estuary stem from industrial development and human land usage, such as mercury contamination, accumulation of dredge spoils, and an oil spill in 2006.

[5] The estuary is situated upon the Squamish First Nation, with an agreement in place between them and the province of British Columbia aimed at ensuring a collaborative effort in managing the park, fostering active communications, developing proactive strategies, providing opportunities for the Squamish First Peoples to share their cultural heritage, and acknowledging the relevance of their community’s stewardship and partnership initiatives.

It contains varied habitats such as marshes, mudflats, intertidal shores, seagrass beds, tidal streams, and barrier beaches.

Its geographical features also contribute to water filtration and thus lead to a more pristine marine environment, as well as mitigating flood risks around the region.

[5] The estuary provides important spawning grounds for salmon and other fishes, as well as terrestrial habitat for native mammals like cougars, beavers, black-tailed deer, and black bears.

In the 1970s, large quantities of dredge spoils material were deposited into the estuary for a proposed coal port that was blocked by the Department of Fisheries and Oceans and never constructed.

Although its primary purpose is to ensure a viable habitat for fauna and flora, recreational activities occur throughout the park too, including various trails, wind sports, and hunting and fishing with vehicular access available.