Editors’ note: This is part of an ongoing series on issues of Native sovereignty before the U.S. Supreme Court. The next entry in the series can be found here.

In Penobscot Nation v. Frey, the Supreme Court has the opportunity to correct a recent First Circuit decision that, if left to stand, would upend established Indian law canons of construction and undermine the principles of sovereign-to-sovereign relations that govern engagement between Native nations and the United States. The First Circuit’s decision would force the Penobscot Nation to cede, without compensation, sovereignty over the only place where the Nation’s fishing rights matter – the Main Stem of the Penobscot River – on the unprecedented theory that inter-sovereign agreements between the United States and Native nations are analyzed differently than formal treaties.

That decision flies in the face of settled precedent and congressional intent – as Co-Chair of the Native American Caucus Representative Sharice Davids (Ho-Chunk Nation) and Vice-Chair Representative Raúl Grijalva outline in an amicus brief filed Jan. 6 in support of the Penobscot Nation’s petition for a writ of certiorari. The brief, filed by the NYU-Yale American Indian Sovereignty Project, where I am a research fellow, and Deutsch Hunt PLLC, argues that the First Circuit’s approach disregards Supreme Court precedent applying uniform canons of construction to inter-sovereign agreements, whether created by treaty or statute. The First Circuit’s decision also ignores modern trends away from the formal treaty process toward “treaty substitutes” in all areas of foreign relations, including relations with Native nations. Rather than apply settled rules that place treaties and treaty substitutes on equal footing, the First Circuit created from whole cloth a separate doctrine for inter-sovereign agreements ratified by statute. If not corrected, the First Circuit’s decision would both violate the sovereignty of the Penobscot Nation and unsettle expectations of other Native sovereigns whose relationships with the United States are governed by non-treaty agreements.

International Law and Sovereignty in Federal Indian Law

The United States’ relationship to Native nations is – and always has been – a relationship between sovereigns, shaped by principles of international law. From the early years of the United States, the new government looked to the laws of nation for guidance on engaging with Native nations; under widely recognized international law principles, the tribes were understood to have inherent sovereignty that was full, independent, and enduring. That sovereignty, which included the right to self-govern, remained with the Native nations unless they voluntarily ceded it.

In the 19th century, Chief Justice John Marshall again looked to international law in a trilogy of U.S. Supreme Court cases that laid the foundations of federal Indian law. In Johnson v. M’Intosh, in particular, Marshall adopted elements of the public international law “doctrine of discovery” to conclude that the United States had exclusive authority over the Native nations, that Native nations retained their inherent sovereignty and right to land, and that only the United States – and not other European powers or private individuals – had the right to alienate Native land title. While Marshall looked to international law for the United States’ exclusionary power, however, he considered relations between the United States and Native nations to be squarely a matter of U.S. federal law. As Professor Maggie Blackhawk, a Sovereignty Project co-director, has observed, Marshall “modified the international doctrine as he domesticated it.”

And, in practice, the United States’ respect for Native sovereignty has been deeply inconsistent, with many periods of U.S. history marked by a “full-bore assault on tribal culture and institutions.” In the Indian Appropriations Act of 1871, Congress – under pressure from U.S. settler interests who saw Native sovereignty as a threat to territorial expansion – unilaterally banned any further treaty-making with Native nations, requiring that all future federal engagement with the tribes be done through statute. Both Congress and the Supreme Court have oscillated between eras of broader and narrower understanding of tribal sovereignty. But, although the specific contours of tribal sovereignty have sometimes shifted, the core principle – that Native nations and the United States engage as sovereign to sovereign – has always remained. Today, the United States continues to profess adherence to principles of government-to-government relations in tribal engagement.

Defining the Penobscot Reservation

The Penobscot Nation has always centered its domain, economy, culture, and spiritual beliefs on the Main Stem of the Penobscot River. So, it’s no surprise the story about the Nation’s fight to protect its aboriginal sustenance-fishing rights begins with two treaties, in 1796 and 1818, in which the Penobscot River was central.

In each treaty with the state of Massachusetts, the Nation ceded lands “on both sides of the Penobscot River” in exchange for nominal compensation. The 1796 treaty promised the Nation blue cloth for blankets, hats, salt, ammunition, corn, and rum, and the 1818 treaty promised four hundred dollars and some items to be delivered in the future. Neither treaty ceded land within the river. In fact, the 1818 treaty expressly granted the citizens of Massachusetts the right to pass and repass along the water – reflecting the fact that the parties understood the water remained Penobscot territory.

When Maine separated from Massachusetts in 1820, the state entered into an agreement with the Penobscot Nation, acceding to the two treaties with Massachusetts. The state of Maine and the Nation subsequently relied on the two treaties for over a hundred years.

Both treaties, however, violated federal law. Under the 1793 Nonintercourse Act, only the federal government could authorize land cessions with tribes. When the Penobscot Nation gained federal recognition in the 1970s, it sought federal confirmation of its reservation borders. The United States, acting as trustee for the Nation, sued Maine for its unlawful taking of lands on either side of the river.

The lawsuit was resolved through negotiations between the state of Maine, the Penobscot Nation, and the United States. The settlement agreement was subsequently codified in two statutes – the Maine Implementing Act and the federal statute ratifying that act, the Maine Indian Claims Settlement Act – collectively known as the “Settlement Acts.” The Implementing Act defined the Penobscot Reservation to include “the islands in the Penobscot River reserved to the Penobscot Nation by agreement with the States of Massachusetts and Maine,” and preserved the Nation’s members sustenance fishing rights within the reservation. Because the settlement disposed of the Nation’s land claims against Maine, Congress’ explicit intent was to reach a “fair and just settlement.”

After passage of the Settlement Acts, both the Nation and Maine repeatedly acknowledged the reservation included portions of the river. In 2012, however, Maine changed its position for the first time. Maine’s Attorney General issued an opinion to state officials indicating the river was not a part of the reservation, and, as such, the state had exclusive regulatory jurisdiction over it.

Following that opinion, the Nation stopped its regular patrols of the river to enforce its ordinances, including those requiring nontribal fishers to obtain permits from the Nation, which left the Nation’s members’ sustenance rights unprotected. Soon after, the Nation sued Maine for declaratory and injunctive relief to protect its on-reservation sustenance fishing, trapping, and hunting rights in the Main Stem of the Penobscot River. The Nation sought a declaration that its land included the waters of the Main Stem, while Maine filed a counterclaim seeking a declaration that the Penobscot Reservation included only the island. The United States intervened in support of the Nation, expressing its intent, under the Settlement Acts, to preserve the Nation’s rights to the Main Stem.

Treaties, Treaty-Substitutes, and Canons of Construction

The First Circuit upheld the district court’s determination that the Settlement Acts reserved only the island uplands, and not the waters or submerged lands, to the Nation. To reach that decision, the court created new and unprecedented rules of interpretation for inter-sovereign agreements that, if upheld, would have far-reaching consequences.

Long-established Supreme Court precedent on Indian canons of construction requires agreements with tribes “be interpreted in light of the parties’ intentions, with any ambiguities resolved in favor of the Indians,” with the terms construed “in the sense that they would naturally be understood by the Indians.” The Court has also held that these canons of construction apply to “treaty-substitutes” and has thus applied them to myriad agreements, statutes, and executive orders. The Court takes the same approach in interpreting agreements with foreign sovereigns, treating Article II treaties, executive agreements, and acts of Congress as equivalent to formal treaties and applying the same principles of treaty interpretation.

Though not a formal treaty, the Settlement Acts codified the settlement agreement between three sovereigns (the Penobscot Nation, the United States, and Maine) and function as a classic treaty substitute. Contravening decisions of the Supreme Court and other circuits, however, the First Circuit did not apply the canons of construction because “the Settlement Acts are not treaties. . . . They are statutes. The treaty canon has no bearing on their interpretation.” As such, the First Circuit stated, the Penobscot Nation’s understandings about the agreement are “beside the point.”

The First Circuit went on to find that the territory of the reservation under the Settlement Acts did not include the waters of the Penobscot River – the place where the Nation’s members have always fished. The First Circuit relied on the dictionary definition of the word “island” (a piece of land) in concluding that the use of the term in defining the reservation required exclusion of the surrounding water.

The First Circuit’s analysis ignored factors that, under an analysis governed by Indian canons of construction – or even ordinary canons of construction – would have cut in favor of the Nation, likely dispositively. For example, the majority found no conflict between its definition of the boundaries of the Nation, excluding the only place the Nation’s members can fish, and the explicit retention of on-reservation fishing rights in the Implementing Act. Rather, the First Circuit reasoned that its inquiry was focused on the definition of the reservation, not the scope of the Nation’s sustenance fishing rights. It is difficult to see how the First Circuit could have reached the same internally contradictory conclusion had it applied the Indian canons of construction, resolving ambiguities in favor of the Penobscot Nation and considering how the Nation would have understood the agreement.

The First Circuit further compounded the conflict by diminishing reservation borders without a clear congressional statement. In McGirt v. Oklahoma, the Supreme Court explained that only “Congress can divest a reservation of its land and diminish its boundaries . . . [O]nce a reservation is established, it retains that status until Congress explicitly indicates otherwise.” The Settlement Acts were never intended to define all Penobscot territory, but instead to resolve relationships governed by treaties that had been entered into illegally. Congress intended to preserve the treaty borders of the reservation and preserve tribal members’ sustenance-fishing rights within the boundaries of the reservation. Nowhere does the statutory text of the Settlement Acts reflect Congress’ intent to cede rights Penobscot Nation had always retained to the submerged lands and waters of the river where its members have always fished. And under the appropriate canons of construction, it would have been impossible to conclude that the Penobscot Nation believed it was entering into an agreement ceding territorial rights it had always held.

The First Circuit’s decision further ignores the United States’ trust responsibility with tribes. In Alaska Pacific Fisheries v. United States, Congress had reserved “the body of lands known as Annette Islands” for the Metlakahtla Indians. The Supreme Court held that Congress’ reservation of lands necessarily included the islands as well as the adjacent waters and submerged land because Congress’ intent was to support the Metlakahtla’s efforts to become self-sustaining. The Penobscot Nation similarly relies on its sustenance activities, which Congress explicitly protected to in the Implementing Act.

Consequences of the Decision

The First Circuit’s decision has dire consequences for the Penobscot Nation, whose members were stripped of their ability to exercise and protect the sustenance rights they have had since time immemorial. The Penobscot Nation is also not the only Native nation with reservation boundaries set by a treaty substitute rather than a formal treaty. As the Appendix to the Sovereignty Project’s amicus brief notes, more than 90 Native nations have reservation boundaries set by statute or executive order. The First Circuit’s decision similarly threatens these nations’ ability to govern sovereign lands and to exercise the rights protected by treaty substitutes.

The First Circuit’s approach to the case also reflects a deeper problem of judicial ambivalence about Native sovereignty. As noted in the Nation’s petition for certiorari,

Curtailing the Nation’s borders by stripping its namesake River from the Reservation is no less offensive and intrusive to the Nation’s core sovereignty than if an international court were to afford Canada exclusive jurisdiction over the entirety of the Great Lakes. Canada could hardly blunt that blow with halfhearted pledges to allow Americans to continue to fish the lakes that it suddenly insists are outside U.S. territory.

The First Circuit’s decision could also introduce uncertainty to non-treaty agreements with foreign sovereigns. As noted at footnote 5 of the amicus brief, the Supreme Court has long applied principles of treaty interpretation equally to Article II treaties, executive agreements, and acts of Congress. And, as Professor Oona Hathaway has documented, much of the United States’ international lawmaking is now authorized through congressional-executive agreements, rather than the formal Article II treaty approval process. Upholding the First Circuit’s decision would open the door to the idea that different types of sovereign agreements are subject to different principles of treaty interpretation, potentially complicating the expectations of foreign states considering agreements with the United States.

A nation’s sovereignty and security are inherently bound up with the right to control its territory. There are few greater threats to national security than the arbitrary loss of territory – and there are few sovereigns whose national security is more precarious than Native nations, sovereigns within a sovereign that have seen their rights eroded time and again. The Supreme Court now has the opportunity to reverse the injustice to the Penobscot Nation and bring the First Circuit’s law in line with long-standing principles of Indian law. It should take it.

IMAGE: The sun rises over Penobscot Bay in Maine on July 31, 2021. (Photo by JOSEPH PREZIOSO/AFP via Getty Images)