No. 16-1498October Term 2018Decided Mar 19, 2019
Washington State Dept. of Licensing v. Cougar Den, Inc.
Washington could not apply this fuel-import tax to Cougar Den because the Yakama treaty protected the transportation at issue.
Case status
- Current stage
- Decided
- Latest event
- Decision released Mar 19, 2019
- What it's about
This case asked whether Washington could impose its fuel-import tax on Cougar Den, a Yakama-owned company that transports fuel by highway from Oregon to the Yakama Reservation. The Supreme Court held that, as applied here, the tax was barred by an 1855 treaty protecting the Yakama Nation’s right to travel on public highways.
Question presented
Whether the Yakama Treaty of 1855 creates a right for tribal members to avoid state taxes on off-reservation commercial activities that make use of public highways.
- Case path
Supreme Court of Washington / Decision released Mar 19, 2019
- Area
Decided Supreme Court case
Briefing
What it's about
Washington tried to apply its fuel-import tax to Cougar Den, a Yakama-owned company that hauls fuel by highway from Oregon to the Yakama Reservation. The Supreme Court said the 1855 Yakama treaty barred that tax as applied here and affirmed the lower court.
Vote
The Court affirmed, but the record provided here does not give a vote count or opinion lineup.
Impact
The decision limits how Washington can tax certain transportation tied to Yakama treaty rights. For example, it affects Yakama-owned businesses that move goods over public highways to the reservation.
What's next
The Supreme Court has finished this case. Washington and lower courts must apply the decision in similar disputes involving the Yakama treaty and highway transportation.
What was the main fight in Washington State Dept. of Licensing v. Cougar Den, Inc.?
The dispute was whether Washington could charge its fuel-import tax when Cougar Den moved fuel by highway to the Yakama Reservation. The company said the 1855 treaty protected that travel.
Who is most affected by this decision in the real world?
Yakama-owned businesses that transport goods over public highways to the reservation are directly affected. State tax officials also must account for the treaty limits recognized here.
What happens next after the Supreme Court's decision?
The case is over at the Supreme Court. Washington must follow the ruling, and lower courts may use it in future Yakama treaty tax disputes.
Decision
What the Court decided
Washington could not apply this fuel-import tax to Cougar Den because the Yakama treaty protected the transportation at issue.
Impact
The decision limits how Washington can tax certain transportation tied to Yakama treaty rights. For example, it affects Yakama-owned businesses that move goods over public highways to the reservation.
Not official Court text.
Opinion documents
Related cases




Grounding
- Grounding
- Primary materials plus reporting.
- Note
- Best-effort analysis: this explainer relies on a mix of primary materials and trusted secondary sources. Official filings and opinions remain authoritative.
- Checked
- Jun 1, 2026
- Method
- Methodology
Primary materials8
Supreme Court docket 16-1498
docket | Jun 1, 2026
Primary case document
Supreme Court document | Jun 1, 2026
CourtListener docket record
docket | Jun 1, 2026
Questions Presented
brief | May 24, 2026
opinion
opinion | Mar 19, 2019
SupremeCourt.gov
official | Jun 1, 2026
SupremeCourt.gov
official | Jun 1, 2026
SupremeCourt.gov
official | Jun 1, 2026