Its Reservation is located 65 miles North of Seattle, Washington on Fidalgo Island.The tribe's population is primarily composed of Swinomish, Lower Skagit, Kikiallus, and Samish peoples and their descendants.

The ancestral bands of the tribe originated in the Skagit and Samish river valleys and nearby coastal areas, including Fidalgo, Whidbey, Camano, and the San Juan islands.

The United States Supreme Court has repeatedly ruled that only Congress – not a President - can reduce the size of a reservation.

[9] In September 2012, the Tribe learned from media reports that “unit trains” of 100 railcars or more were beginning to cross the Reservation.

By April of 2015, BNSF was reportedly running six 100-car “unit trains” per week across the Reservation, more than four times as many railcars daily as permitted by the easement.

The tracks are adjacent to the Tribe’s economic center, including a hotel, casino, gas station, and cannabis dispensary.

The intended development of this economic center was one of the primary reasons for the limitation of the number of trains and cars incorporated into the easement.

Following the decision of the Court of Appeals, the District Court ruled in 2022 that the trespass was intentional and conducted a trial in March 2023 to determine whether BNSF’s trespass over the Swinomish Reservation between September 2012 and May 2021 was also willful, conscious, and knowing, which would allow the tribe to seek disgorgement of BNSF’s ill-gotten gains.

The District Court then scheduled a trial that began June 3, 2024 to determine BNSF’s wrongful financial gain from its trespass on the Swinomish Reservation.

In a ruling issued on June 6, 2024, District Court Judge Robert S. Lasnik ordered that BNSF disgorge total trespass profits of $394,517,169 to the Swinomish Indian Tribal Community.

Specifically, the Court ordered that BNSF disgorge net profits of $362,267,169 attributable to its trespass across the Swinomish Reservation from September 2012 to May 2021.

In addition, the Court ordered that BNSF disgorge a further amount of $32,250,000, representing the use value of the aftertax profits arising from the trespass.

[12] The chair, vice-chair, secretary, and treasurer form the executive committee and are elected annually within the senate.

The reservation is located on Puget Sound, on the southeastern side of Fidalgo Island in Skagit County, Washington.

Global warming and its effects, such as ocean acidification, affect the development of shells of marine animals vital to the Swinomish food supply.

They also hold the traditional First Salmon Ceremony each year, celebrating the beginning of the fishing season and protecting the fishermen of the community.

The Swinomish Tribe announced in February 2024 their plans to sue the EPA for failing to effectively reduce stream temperatures in the Skagit River watershed.

[36] The ruling recognized the tribes as natural resources co-managers with the State of Washington with an equal share of the harvestable number of salmon returning annually.