This is a listing of links to the indexes of the Chinese Exclusion Act case files at the National Archives at Seattle. It includes everything that has been indexed up to February 2019.
[Although the Seattle files have been indexed through mid-March 2020, my copy only goes through February 2019. The National Archives at Seattle is closed because of the COVID-19 pandemic. When it reopens, the indexing project will continue where we left off in March 2020 and I will post an updated version on the index.]

There are over 50,000 Chinese Exclusion Act case files at the National Archives at Seattle. Most of the files are for Chinese who entered the United States at the Port of Seattle but they also include files from Port Townsend, and Sumas, Washington; Portland, Oregon; Helena, Montana; Portal, North Dakota; and Vancouver, British Columbia, Canada. The files are grouped by the port of arrival.

All 34,711 of the files for Seattle have been indexed by the name on the case file and the file number. About two-thirds of these files have also been indexed by the other names the person may have gone by (married name, school name, or aliases), certificate of residence or identity number, beginning and ending dates of the file; date, port, and vessel for last entry; residence, occupation (laborer, student, traveler, diplomat, merchant, other); citizenship category (native born, child of native born, spouse of child of merchant); gender, photograph in file, interrogation, disposition (admitted, rejected/appealed, court, deported, did not return, unknown, deceased, applied to leave/disposition unknown), and comments. The comments area notes other documents found in the files, such as, maps, family group photos, marriage/birth certificates, and passports.

Seattle, WA Index [34,711 files]
Seattle, WA, RS-Apps Index [8,320 files – this is a subseries of the Seattle files]
Port Townsend, WA Index [115 files]
Sumas, WA Index [827 files]
Portland, OR Index [3,795 files]
Helena, MT Index [187 files]
Portal, North Dakota Index [1,274 files]
Vancouver, British Columbia, Canada Index  [1,084 files]

The Chinese Family History Group of Southern California also has indexes for Chinese Exclusion Act case files from the University of California Berkeley Library database and National Archives facilities at Boston, New York, Portland, Riverside, San Bruno, Seattle, and Vancouver and the INS San Francisco Index of Certificates of Identity 1909-1938. [The Seattle index was taken from an earlier date in the indexing process.]

Explore Chinese Family History Group of Southern California site. They have many resources listed.