Background & Facts
In 1908, Congress passed the Cheyenne River Act, opening 1.6 million acres of "surplus" land within the Cheyenne River Sioux Reservation to non-Indian settlement. Decades later, the question arose: did the 1908 Act diminish the reservation — meaning the opened lands were no longer Indian Country and were subject to South Dakota state criminal jurisdiction — or did the reservation boundaries remain intact?
John Bartlett, a tribal member, was charged in South Dakota state court with attempted rape committed on land within the original reservation boundaries that had been "opened" by the 1908 Act. Bartlett challenged state jurisdiction, arguing the land was still Indian Country and thus subject only to federal/tribal jurisdiction.
The Supreme Court ruled unanimously for Bartlett — and articulated the framework that would govern all future reservation-disestablishment questions, including the 2020 McGirt decision.
The Court's Holding — The Solem Three-Step
Justice Marshall established a three-step framework for determining whether Congress has diminished a reservation. The presumption is against diminishment — reservations remain intact unless Congress has clearly indicated otherwise. Courts must look at:
Step 1 — Statutory Text:
Did Congress use language of "cession, surrender, or extinguishment"? Did the statute include an unconditional commitment to compensate the tribe for lost land? Express diminishment language is the strongest evidence.
Step 2 — Historical Context:
What did Congress intend at the time? Legislative history, contemporaneous understanding of the act, and surrounding circumstances inform the question — but never substitute for clear text.
Step 3 — Subsequent History & Demographics:
How have the lands been treated since? But this is the WEAKEST evidence. Demographic change and state assumption of jurisdiction cannot create disestablishment that Congress did not authorize.
Key Language
"Once a block of land is set aside for an Indian reservation and no matter what happens to the title of individual plots within the area, the entire block retains its reservation status until Congress explicitly indicates otherwise."
"The most probative evidence of congressional intent is the statutory language used to open the Indian lands. Explicit reference to cession or other language evidencing the present and total surrender of all tribal interests strongly suggests that Congress meant to divest from the reservation all unallotted opened lands."
"We have never been willing to extrapolate from a statute that merely opens reservation lands to settlement the inevitably greater intent of disestablishing those lands."
Why Solem Is Doctrinally Upstream of Everything ATN Cares About
Solem is the case McGirt was decided under. The framework Justice Gorsuch applied in McGirt v. Oklahoma (2020) — leading to the conclusion that the Muscogee (Creek) Reservation had never been disestablished — is Solem's framework, virtually unchanged. Solem set the rule. McGirt reaffirmed it 36 years later in dramatic fashion.
What Solem gives ATN at Mendocino:
- 1. The presumption is against diminishment. When California or Mendocino County argues that the Mendocino Indian Reservation has effectively dissolved through allotment, fee patenting, demographic change, or state assumption of jurisdiction, Solem says: not so fast. The presumption runs the other way. The county must point to express congressional language disestablishing the reservation — and it cannot, because no such statute exists.
- 2. State conduct cannot create disestablishment. Step 3's emphasis on the weakness of demographic and historical evidence is critical. Even if California has exercised PL280 jurisdiction over reservation land for 70+ years, that exercise of state authority does NOT diminish the reservation. State treatment is the weakest evidence under Solem.
- 3. Allotment and fee-patenting did not extinguish reservation status. Solem's central holding is that Congress can open lands to settlement WITHOUT disestablishing the reservation. Many parcels at Mendocino passed into fee status during allotment and Termination eras. Under Solem, that fact alone does not extinguish the reservation boundaries that contained those parcels.
- 4. This is the McGirt template applied to California. McGirt ruled that the entire eastern half of Oklahoma — millions of acres, including Tulsa — was still Indian Country because no statute had ever disestablished the Muscogee Reservation. The same logic applied to Mendocino would treat the entire historic 36-square-mile reservation as still-existing Indian Country, regardless of the patchwork of fee titles within it.
- 5. The federal "express action" requirement runs everywhere. Crow Dog (1883) said federal jurisdiction needs express congressional action. Solem (1984) said reservation diminishment needs express congressional action. McGirt (2020) said disestablishment needs express congressional action. The pattern is unbroken: federal Indian law presumes tribal/reservation status persists unless Congress unambiguously took it away.
For PL280 specifically: Solem cuts hard against any argument that PL280's transfer of jurisdiction somehow disestablished or diminished California reservations. PL280 is a jurisdictional statute, not a disestablishment statute. It transferred adjudicatory authority but said nothing about reservation status. Under Solem, that silence preserves the reservation. ATN's Mendocino Indian Reservation is still a reservation regardless of California's 70 years of jurisdictional exercise.
Related Cases
- McGirt v. Oklahoma (2020) — Modern application of Solem; held that the Muscogee Reservation was never disestablished
- Ex parte Crow Dog (1883) — Original "express action" rule that Solem extends to disestablishment
- Cherokee Nation v. Georgia (1831) — Source of the trust doctrine that grounds the anti-diminishment presumption
- City of Sherrill v. Oneida (2005) — A counter-pull on long-alienated land; distinct from formal diminishment