The courts
Proposals to split the Ninth Circuit
Proposals to divide the Ninth Circuit have asked Congress to weigh geography, judicial workload and appellate administration. Their effects depend on the boundaries and judgeships in each plan.
The geography behind the proposals
Wikipedia's overview of the Ninth Circuit describes it as the largest federal court of appeals, covering nine states and two territories with 29 active judgeships. Its jurisdiction includes Alaska, Arizona, California, Hawaii, Idaho, Montana, Nevada, Oregon and Washington, as well as Guam and the Northern Mariana Islands. These boundaries place a wide range of district courts within a common appellate circuit.
Circuit geography determines which appellate court reviews decisions from those district courts. Reorganizing a circuit therefore involves more than a change in its name or administrative headquarters. A proposal must assign districts and judges, address how the new courts operate, and consider the distribution of cases. Size supplies a reason to examine those questions, but it does not alone determine the effect of a proposed boundary.
The federal courts guide explains the distinction between district and appellate courts. The split proposals concerned the arrangement of appellate institutions rather than the substantive wording of an environmental statute. The debate nevertheless mattered to the organization of the courts that hear environmental and other federal disputes.

The legislative record
The Congressional Research Service report on the split proposals examined bills in the 109th Congress. Its legislative account records that the House passed a budget-reconciliation measure containing split language in November 2005, but that language was removed during House-Senate negotiations in December 2005. The initial House action and the removal of the provision were separate legislative events.
CRS's report identifies H.R. 211, H.R. 212, H.R. 3125, H.R. 4093, S. 1296, S. 1301 and S. 1845 as the remaining split proposals under consideration. The report compared the proposed circuit arrangements rather than treating every bill as the same plan. Different allocations of states and judgeships could produce different operational effects.
The CRS account records that the House Judiciary Committee reported H.R. 4093 on February 8, 2006, and that the Senate Judiciary Committee held a hearing on S. 1845 on September 20, 2006. The report also states that neither chamber passed legislation splitting the circuit during the 109th Congress. Committee action, a hearing, passage of a provision and an enacted reorganization should not be collapsed into a single outcome.
What supporters and opponents compared
CRS described proponents as arguing that reduced geography, population and caseloads would improve judicial administration. Opponents argued that the circuit's existing management practices could handle its workload and that dividing it would duplicate staff and administrative functions. The report presented these as competing claims about organization and performance, rather than as an agreed measure of how well the court operated.
The comparison also involved legal continuity across the western states. Opponents valued a common circuit for the region, while supporters emphasized the possibility of closer case management within smaller institutions. Those arguments concern different aspects of administration. An account of the debate needs to preserve the distinction between a common body of circuit law and the practical work of handling appeals.
CRS cautioned that efficiency was not a universally defined term in the debate. A measure based on filings per judgeship differs from a measure based on the time to disposition. Case complexity, the availability of senior judges and administrative practices can further affect the relationship between caseload and work. A comparison should identify what it measures before drawing a conclusion from the court's size.
How a boundary changes the denominator
The report's caseload analysis did not assume that a split would evenly distribute work. CRS described some proposed arrangements as leaving a new Ninth Circuit with a higher load per authorized judgeship than either the existing circuit or the proposed companion circuit. This is a structural question: removing territory can remove both cases and judgeships, and the resulting ratio depends on the particular allocation.
That point distinguishes a proposal to split a circuit from a proposal to add judgeships. Either can affect administration, but they change different parts of the system. The judgeships and vacancies page addresses the creation and filling of judicial positions. A boundary proposal must still be evaluated on its own assignment of those positions and cases.
En banc review and later proposals
Wikipedia's Ninth Circuit article describes the court's limited en banc procedure as using the chief judge and 10 randomly selected judges, in contrast to the usual participation of all active judges in other circuits. The article also notes that full en banc consideration is available in limited circumstances. The procedure is an institutional feature, not a description of the merits of any particular decision.
The same Ninth Circuit article lists later proposals including S. 525 in 2007 and H.R. 196 in 2017. It describes a recurring proposed boundary that would retain California, Hawaii and the Pacific territories in the Ninth Circuit while assigning the other western states to a new circuit. Listing a proposal does not establish that Congress enacted it.
The legislative history thus concerns alternatives to a continuing court, with different arguments about geography, workload, expense and review procedures. The D.C. Circuit page offers a comparison with another regional appellate court whose institutional role arises from a very different geographic jurisdiction.