United States v. California
The Supreme Court entered a fifth supplemental decree in its decades-old original case over ownership of the seabed off California, adopting a jointly agreed set of precise coordinates marking the boundary between state and federal underwater land.
The order updates and pins down boundary lines first set in 1947 and refined several times since, giving both governments a fixed, non-shifting line for regulating offshore oil, mineral, and resource rights.
How it got here: The United States and California jointly moved the Supreme Court, exercising its original jurisdiction over the long-running boundary dispute, to enter a supplemental decree.
The Case in Depth
What happened
Since 1947, the United States and California have disputed and then cooperatively defined which government owns the submerged lands, minerals, and resources beneath the Pacific Ocean off California's coast. Earlier decrees in 1947, 1966, 1977, 1978, and 1981 addressed portions of this boundary. This fifth supplemental decree, requested jointly by both governments, sets out detailed coordinates completing that boundary definition.
The question before the Court
Exactly where does the underwater boundary line run between California's coastal waters and federal waters off the Pacific coast?
The Court's answer
The Court's decree fixes the answer through a long list of precise geographic coordinates rather than a general rule: it approves the boundary lines jointly proposed by the United States and California, running along the mainland coast and around several offshore islands (including the Farallon and Channel Islands). Everything landward of these lines belongs to California; everything seaward belongs to the United States, except for statutory exceptions under the Submerged Lands Act.
This is a technical, cooperative resolution rather than a contested legal ruling—both parties agreed on the exact coordinates, and the Court's role was to formally enter them as a binding decree. The boundary is now permanently fixed at these coordinates and will not move with future natural changes to the coastline.
Curious how the Court got there? See the step-by-step legal reasoning →
Why it matters
This decree resolves practical questions about which government—state or federal—controls leasing, drilling, and resource rights in specific offshore areas, including near the Channel Islands and Farallon Islands. Businesses seeking offshore permits and regulators enforcing environmental or mineral rules now have an exact, fixed boundary rather than one that shifts with the coastline.
What changes now
The boundary described in this decree is now fixed and immobilized at the specified coordinates under the Submerged Lands Act, meaning it will not move even if the natural coastline changes. The Court retains ongoing jurisdiction to resolve any future disputes or issue further orders needed to enforce or clarify the decree, but no further action is expected unless a dispute arises.
How the Court got there
The legal reasoning, step by step
- The Court exercised its original jurisdiction over the ongoing dispute between the United States and California regarding ownership of submerged coastal lands, a case it has overseen through a series of decrees since 1947.
- Because both governments jointly agreed on and moved for the specific boundary coordinates, the Court did not need to resolve any contested legal question but simply approved the parties' agreed technical description of the line.
- The Court applied the Submerged Lands Act's requirement that, once such a boundary is set by decree, it becomes fixed and immobilized rather than shifting with future changes in the natural coastline.
- Based on the parties' joint submission, the Court adopted detailed coordinate-based descriptions of the boundary for the mainland coast and for offshore islands, formalizing them as the operative federal-state boundary.