It has been 38 years since the tribe gain federal recognition, which does not require a subsequent grant of a reservation, The Daily Herald reports.
The Stillaguamish have been trying for nearly 30 years to take that next step.
Their first attempt was rejected by the U.S. government because one of the properties did not meet all their requirements. The tribe of nearly 300 members has been trying ever since then to make it happen.
"Things had stalled due to many factors," tribal Chairman Shawn Yanity said, including "the inner workings with the (U.S.) Department of the Interior and the tribe's leadership at the time."
While the reservation process was stalled, members of the tribe found homes throughout Snohomish County, many in Arlington, Stanwood and Marysville.
This year, when the tribe tried again it succeeded. The U.S. Bureau of Indian Affairs released its Stillaguamish Reservation Proclamation on July 30.
The Stillaguamish's new 64-acre reservation includes its Angel of the Winds Casino that was built on tribal land.
"It kind of gives us that anchor on the map," Yanity said.
Having a reservation doesn't really change the day-to-day operations of the tribe, Yanity said. But it's part of the process for centralizing services like public safety, health care and a community center.
"It lets people know we're obviously here. It encompasses the area that is already commercialized around the casino," said Jon Hare, who manages real estate for the tribe. "I think really what it does is put a bold line on it jurisdictionally."
Tribal trust lands are somewhat scattered, Hare said, but the tribe hopes to unify.
Having a reservation can also help the tribe qualify for grants or public safety funding specifically earmarked for reservations, Yanity said.
The tribe may try to expand the Stillaguamish Reservation in the future.
"We started small, but if the tribe wants, they can do the process all over again to add more property," Hare said.
New housing and a community center are planned on 80 acres of land east of Angel of the Winds Casino, Yanity said. The planned development eventually could be added into the reservation. The tribe would also like to have a clinic on its reservation, he said.