4 U.S.C. § 111

1. (a)The United States consents to the taxation of pay or compensation for personal service as an officer or employee of the United States, a territory or possession or political subdivision thereof, the government of the District of Columbia, or an agency or instrumentality of one or more of the foregoing, by a duly constituted taxing authority having jurisdiction, if the taxation does not discriminate against the officer or employee because of the source of the pay or compensation.
2. (b)Pay or compensation paid by the United States for personal services as an employee of the United States at a hydroelectric facility—shall be subject to taxation by the State or any political subdivision thereof of which such employee is a resident.
   1. (1)which is owned by the United States;
   2. (2)which is located on the Columbia River; and
   3. (3)portions of which are within the States of Oregon and Washington,
3. (c)Pay or compensation paid by the United States for personal services as an employee of the United States at a hydroelectric facility—shall be subject to taxation by the State or any political subdivision thereof of which such employee is a resident.
   1. (1)which is owned by the United States;
   2. (2)which is located on the Missouri River; and
   3. (3)portions of which are within the States of South Dakota and Nebraska,