Rider, et al. v. Oxy USA, et al.

Circuit 10May 5, 2026

Split Score

SplitScore: 47/100

Case Summary

Disposition

Reversed

The Tenth Circuit reversed the district court’s denial of class certification in a royalty-underpayment suit arising out of a 2008 settlement between Kansas royalty owners and OXY USA. Applying its newly announced Cline v. Sunoco standard, the court held that Rule 23 does not require an "administrative feasibility" showing for ascertainability and directed the district court to certify the proposed class on remand.

View Full Opinion Document (PDF)

Circuit Split Identified

Legal Issue

Whether Rule 23’s implicit ascertainability requirement includes a separate "administrative feasibility" component that obligates the proponent of class certification to show an administratively workable method of identifying class members.

Circuit Positions

Circuit 3

Ascertainability requires a reliable, administratively feasible mechanism for identifying each class member in addition to a clear, objective definition.

Circuit 7Circuit 10(this circuit)

Ascertainability only requires a clear, objective class definition; no separate administrative-feasibility showing is necessary.

Conflict Summary

The Third Circuit requires both an objective class definition and proof of a reliable, administratively feasible mechanism for identifying class members, while the Seventh Circuit—and now the Tenth Circuit—hold that ascertainability is satisfied so long as the class is defined by clear, objective criteria, rejecting any additional administrative-feasibility prerequisite.

Parties & Counsel

Parties

Appellant:Cherry Rider, R.W. Lucas, and Cathy Lucas (trustees of the Cherry Rider Family Trust and the R.W. Lucas and Cathy Lucas Living Trust)
Appellee:OXY USA, Inc.; Merit Energy Company, LLC; Merit Hugoton, L.P.

Legal Counsel

Appellant:David G. Seely, Ryan K. Meyer, Emily K. Arida (Fleeson, Gooing, Coulson & Kitch, L.L.C.); Erick E. Nordling (Kramer, Nordling & Nordling, LLC)
Appellee:Daniel M. McClure, James M. Shultz, James V. Leito IV, Peter B. Siegal (Norton Rose Fulbright US LLP); Robert W. Coykendall, Will B. Wohlford (Morris, Laing, Evans, Brock & Kennedy, CHTD.); James M. Armstrong (Foulston Siefkin LLP); Mark Rodriguez, Maryam Ghaffar (Beck Redden LLP)