"A treaty more than 150 years old shields tribal businesses from Washington state's gas tax, the Supreme Court ruled today.
In a case with implications for other tribes and state laws, the high court issued a split opinion siding with tribal gas retailer Cougar Den Inc. over Washington officials.
The Evergreen State and the company have been locked in a dispute for years over whether Cougar Den, run by a member of the Yakama Nation, must pay the state's per-gallon tax on motor fuel delivered from Oregon to the reservation in south-central Washington.
The tax applies to gas that crosses state lines, but the company argued that an 1855 treaty with the tribe prevents the state from restricting tribal members' ability "to travel upon all public highways." Cougar Den ships the fuel on public highways and cannot be taxed for that activity, the company said."