Methodology - April 9, 2026

About this Project

The Supreme Court Indian Law Database has two primary functions. First, it compiles a comprehensive and searchable database of all federal Indian law cases adjudicated by the United States Supreme Court. Each case is placed into one or more categories that broadly define the issues, doctrines, and understandings at the heart of the case. Second, it lists the Supreme Court Justices, the cases within the database in which an individual justice participated, and whether that individual justice wrote an opinion, concurrence, or dissent in a particular case. The Database is a resource for academics, practitioners, policymakers, tribal citizens, or anyone who is invested in or curious about this body of law and its relationship to the U.S. Supreme Court.

Definition of Indian Law

The first and most important thing to note — about the database’s definition of Indian law in particular and this project in general — is that there is room for rigorous debate and honest disagreement about where to draw the boundary lines. Based on our methodology, further defined below, we are comfortable asserting that this website offers a comprehensive list of Indian law Supreme Court cases. Nonetheless, in a continuing effort to refine and improve this website, we are open to your comments and suggestions. This includes, but is not limited to, whether a case should be included on the list, whether a case should be excluded from the list, and whether a case is labeled properly. We also urge you to treat this resource not as infallible or definitive, but rather as an important and useful tool to begin or continue your own research. We also ask that if you would like to offer comments or suggestions, you also read this methodology section and our definitions for our categories carefully. The easiest way to reach out about the project is by contacting Keith Richotte at richotte@arizona.edu.

For purposes of this database, “Indian law” is defined as cases that define, refine, or rely upon the field of federal Indian law. Such cases tend to either reach into Indian country or involve significant Native participation.

This definition is broad and covers a lot of ground; however, not every case with Native involvement is an “Indian law” case. For example, Hickory v. United States, 151 U.S. 303 (1894) and Thompson v. United States, 155 U.S. 271 (1894) are cases that are excluded from the database because while they involve Native defendants, they are criminal law cases involving issues of criminal procedure or the definition of crimes that do not define, refine, or rely upon the field of federal Indian law. Another example of a case that was consciously excluded is Cappert v. United States, 426 U.S. 128 (1976). This case is about the Reserved Water Rights doctrine, which Chief Justice Warren Burger notes, “applies to Indian reservations and other federal enclaves, encompassing water rights in navigable and nonnavigable streams.” Id. at 138. However, the dispute is between the federal government and a non-Native landowner with no direct impact on Native America. The mere mention of a doctrine that happens to apply within Indian law does not define, refine, or rely upon the field.

Case Inclusion Methodology

This website includes only U.S. Supreme Court Indian law cases. Determination of cases used for this project was largely completed in four phases.

Phase One

To capture potential Indian law cases, researchers searched within classification systems provided by the two main legal research platforms, LexisNexis and Westlaw. Both platforms provide topical classification and use a hierarchical scheme to organize areas of law from broad to narrow. For both platforms, researchers used the broadest category to capture the most cases:

• Under the West Key Number System, researchers used the category “Indians,” key number 209. Researchers pulled all U.S. Supreme Court cases listed under this category and added those cases to a master list that was then compared to cases from LexisNexis’s classification system.
• Similarly, using LexisNexis’s classification system, Search by Topic, researchers used the category “Native Americans” to pull a list of cases that the research database considered Indian law. Researchers pulled all Supreme Court cases listed under this category and added those cases to a master list that was then compared to cases from the West Key Number System.

At the end of Phase One, researchers had identified 573 potential Indian law cases.

Phase Two:

Recognizing that the initial search did not capture all U.S. Supreme Court cases that fell under the project’s definition of Indian law, researchers performed a natural language search on each research platform search using the terms “Indian” and “Native American.” Researchers compared the results of this search with the list that had already been compiled in Phase One. After eliminating duplicate entries, researchers added the new cases to the original list.

At the end of Phase Two, researchers had identified 2,813 potential Indian law cases.

Phase Three

Once the master list was compiled, researchers individually conducted an examination of all cases in the master list to determine if they could be classified as an “Indian law” case. Pursuant to the project’s defined criteria, a case was considered “Indian law” if it defined, refined, or relied upon the field of federal Indian law.

• During the initial determination of a case’s inclusion, the researchers aimed to be overinclusive, considering the broad intended audience for the project. Any results that were not legal opinions, such as denials of certiorari or references to amicus briefs, were removed from the search results unless they contained substantive discussion that met the project’s definition of Indian law.
• At this stage, researchers did not read every word of every case but rather performed a cursory search, reviewing the parties and issues present in the cases. Researchers went through the master list of cases that had been compiled in Phases One and Two and marked each case as include (meaning it was Indian law), questionable (meaning inclusion was unclear), or do not include.
• Once each of the researchers had gone through the master list of cases, each researcher’s list of include, questionable, and do not include was combined. At the end of Phase Three, researchers had identified 776 potential Indian law cases.

Phase Four:

Phase Four involved two parts: (1) giving each case a closer read and (2) categorizing them. Categories are listed below.

While categorizing the cases, researchers considered again whether each case should be included in the database. For cases where each researcher categorized the case as “Not Indian Law,” the case was automatically excluded. For cases where one or two out of the three researchers participating in this phase categorized the case as “Not Indian Law,” the case was reviewed and discussed, and a decision was made as a group for inclusion in the database.

After the final list of cases to include in the database was complete, researchers compared their list of cases to cases listed under Washington University Law’s Supreme Court Database, using the “Indians” and “Indians, state jurisdiction over” categories. Discrepancies identified from this comparison were reviewed to determine if they should be included. Cases that should be included were reviewed in the same manner as the other cases in Phase Four and categorized accordingly.

At the end of Phase Four, there were 682 cases.

Once the list of cases was complete, researchers enhanced the dataset by integrating information from the Washington University School of Law’s Supreme Court Database. Cases were matched based on citation, and variables, including the participating U.S. Supreme Court justices and their voting behavior, were incorporated into the dataset. In addition, researchers retrieved URLs for the full text of each case using the CourtLister’s API.

Categorization Methodology

Researchers for this project developed broad categories into which the different U.S. Supreme Court Indian law cases could fit. During Phase One and Phase Two of Case Inclusion, researchers kept note of recurring topics, themes, and areas of the law that could be potential categories. Based on this, as well as researchers’ individual knowledge of Indian law from their experiences as teachers and students within the Indigenous Peoples Law and Policy Program at the University of Arizona School of Law, researchers developed a list of 43 categories for the database.

After Phase Three of Case Inclusion three researchers read each case to determine which of the categories each case fit into. This took place from November 2024 to May 2025.

Once all of the cases had been read and categorized by each of the researchers and the non-Indian law cases were removed (as described in Phase Four of Case Inclusion), researchers combined their collective categorizations for each case to see where there was agreement and disagreement. Where each researcher agreed on a category, that category was added to the list of “final categories” for the respective case. Where one or two out of three researchers agreed on the case, that case was marked for further review. From May to July 2025, two researchers, Professor Keith Richotte and Zoë Wise, read and reviewed each of the marked cases to determine where there was agreement or disagreement on categories. Where disagreement on a category existed even after reviewing the case, the researchers discussed their reasoning for listing each case in that particular category until they reached a consensus. During this process, researchers refined their definitions and understanding of each category. Organizational Methodology This project is organized by case citations and categorized based on broad areas of importance in Indian law cases. Additionally, the database is structured to reflect the participation of each Supreme Court Justice in these cases. This organization system allows users to navigate and analyze the cases based on both desired identifiers and judicial opinions.

1. Case Identifiers: The database includes the name, citation, and year of each decision. Citations are to each case’s listing in the U.S. Reports. Users can search by case name to find specific cases. Users can also click on case names to find further information about a particular case, or click on a case’s citation to be taken to the text of the opinion.
2. Categories: This website categorizes each case according to 43 broad but defined categories: (1) Alaska; (2) American Citizenship; (3) Art/cultural property; (4) Canons of Construction; (5) Civil jurisdiction; (6) Claims against the U.S.; (7) Commerce Clause; (8) Contracts; (9) Criminal jurisdiction; (10) Depredations/Individual Claims Against Tribal Nations; (11) Doctrine of Discovery; (12) Domestic Dependent Nations; (13) General Crimes Act; (14) Hawaii; (15) Indian Agents/Administrative law; (16) Indian Child Welfare Act; (17) Indian Civil Rights Act; (18) Indian Claims Commission; (19) Indian Country; (20) Indian Gaming Regulatory Act/gaming; (21) Indian Reorganization Act; (22) Indian Self-Determination and Education Assistance Act; (23) Indian Title/Occupancy; (24) Indianness/Identity; (25) International law; (26) Jurisdiction (other); (27) Laches (statute of limitations); (28) Land/allotment/grants of land; (29) Liquor; (30) Major Crimes Act; (31) Natural Resources; (32) Plenary Power; (33) Public Law 280; (34) Religion; (35) Sovereign immunity; (36) States/Authority of states; (37) Taxes; (38) Termination; (39) Treaties; (40) Tribal citizenship; (41) Tribal courts; (42) U.S. Constitution; (43) Wardship/Trust; . Users can click on each category to find a listing of each case that falls within that category.
3. The Participation of the Justices: Each individual case entry includes a breakdown of the votes cast by each Justice, including when a justice wrote an opinion, concurrence, or dissent in a case. Users can also use the listing of historical U.S. Supreme Court Justices to find individual Justices, and click on their names to be taken to a list of Indian law cases participated in.