Here is the petition in Confederated Tribes and Bands of the Yakama Nation v. Yakima County:

Yakama Nation Cert Petition

Question presented:

The United States reassumed Pub. L. 83-280 criminal jurisdiction over crimes involving Indians within the Yakama Reservation from the State of Washington pursuant to 25 U.S.C. § 1323, on April 19, 2016. Years later, federal officials re-interpreted the scope of that federal reassumption to allow the State of Washington to once again exercise criminal jurisdiction over Indians within the Yakama Reservation any time a non-Indian is involved in the crime.The question presented is:

Can the United States change the scope of its reassumption of Pub. L. 83-280 jurisdiction in Indian Country years after the reassumption became effective under 25 U.S.C. § 1323 without the Yakama Nation’s prior consent required by 25 U.S.C. § 1326?

Lower court materials here.

Update (3/4/21):

Brief in Opposition

Update (3/16/21):

Yakama Reply