History
The land surrounding this region of the cascades was originally Muckleshoot territory. A Lushootseed-speaking tribe, a part of the Coast Salish peoples of the Pacific Northwest. Original territory spanned along the Green and White Rivers, and area surrounding Tahoma- Mt. Rainier. Currently, the Muckleshoot tribal reservation is located in the Auburn area. The Muckleshoot Tribe is a group comprised of many tribes in the area surrounding the lush White River Valley:

White River Valley tribeS
Stkamish / Skekomish (Steq-ABSH) ("People of the log jam", named after the village Steq ("log jam") on the White (now Green) River in the Kent vicinity, the people of Steq were the Steq-ABSH; Settlers and government officials anglicized "Steq-ABSH" into Stkamish and applied the term to all villages between Auburn and Renton Junction.

Smulkamish / Smalhkamish ("People of White River", named after the term that referred to the former course of the Upper White River) - They lived in villages on the present Muckleshoot Indian Reservation and near present-day Enumclaw)

Skopamish (Skop-ABSH / Skwohp-AHBSH) ("The People of the variable stream" or "Green ('fluctuating') River People". They were also known as the Green River Indians, related to their territory.) - They lived in the central Green River Valley, mostly above the former confluence near present-day Auburn. The term skop means "first big and then little," in apparent reference to fluctuations of the Green River. Another source says their name is derived from the village name ill-AHL-koh ("confluence" or "striped water") at the historic confluence of the White and Green rivers at the present-day town of Auburn, possibly from the striped appearance of the Green River below the confluence before the waters merged.

Tkwakwamish / T'Qua-qua-mish (along the headwaters of the Puyallup River)

Yilalkoamish tribe

Dothliuk (they lived in the area of South Prairie, Washington, south of the mouth of the Cole Creek at its confluence with South Prairie Creek, a Carbon River tributary)
Culture
Also skilled in hunting, fishing was the main specialty of traditional Coastal Salish life. Specifically revolving around gathering, curing, and trading salmon with other tribes. Salmon is still treated with reverence to this day, as it was central to survival in Pacific Northwest.

Still observed to this day, the First Salmon Ceremony is celebrated by the sharing of a Spring Chinook- remains are then returned back to the river from which it was caught. This is to honor the salmon, and give back to the land so that it can keep providing for its people. Another ceremony is for the first-caught salmon to be roasted into ashes- which are given back to the waters it was caught. The nutrients return back into the land, to nurture future generations and the next round of new propagation.

As the Pacific Northwest abundantly supplied seemingly endless resources for food, it also allowed for a rich culture of craftsmanship and visual storytelling through artwork. Popular crafts include weaving, woodcarving, basket-making.

Colonization
Life was radically altered following the first encounters with European traders. Decimated by newly-introduced infectious diseases, the native population suffered in the mid-nineteenth century.

Settlers began claiming land as their own, and relationships began to deteriorate. The Muckleshoot allied with other local peoples in an attempt to preserve their rights in the Puget Sound Indian War (1855–1856), but were forced into a tiny reservation near present-day Auburn, Washington.
Present Day
Thanks to the Boldt Decision, the federal district court upheld the right of the Muckleshoot and other Treaty peoples to fish from the rivers of the region and hunt in these territories once again. Designating the Muckleshoot people as co-managers of the King County watershed, rights were restored for fishing and hunting in their "Usual and Accustomed" ancestral hunting and fishing grounds.

While this moderately improved the tribe's economic standing, tribal members are not exempt from adverse effects on the environment, especially concerning river water quality, a product of urbanization and industrialization. Dams on rivers had decreased the fish populations that could get upstream to spawn, and water quality in the rivers have declined. While they continue to fight for preserving the paths of ancient salmon runs, the Muckleshoot also found other venues to improve their economy.

Taking advantage of their proximity to Seattle and other urban centers, Casino and bingo parlors have opened up on their reservation. Revenues from the reacquired lands near the reservation have helped support welfare and education of their people.
Source
Johansen, Bruce E (2015). Up from the Ashes: Nation Building at Muckleshoot (1st ed.). Seattle, WA: Seattle Publishing. ISBN 978-0-9857764-1-1.