## Facts

- In 1944, grantors conveyed land in Campbell County, Wyoming, reserving “one-half of all oil and commercial gravel rights.”
- Decades later, coalbed methane and other gas development prompted disputes among successors in interest over whether the 1944 reservation included gas.
- Successors aligned with the grantors argued “oil rights” was used locally to mean all mineral rights, including gas, and offered testimony about industry shorthand.
- Successors aligned with the grantee relied on the deed’s text and evidence that contemporaneous recorded instruments typically specified “oil and gas” when both were intended.
- The district court construed the reservation as covering oil and commercial gravel only, quieted title to the gas in the grantee-successors, and rejected related claims premised on a gas reservation.
- A related action involving Mullinnix, LLC—whose asserted mineral claims depended on the broader reading of the 1944 reservation—was consolidated on appeal.

## Issues

1. Whether a deed reservation of “one-half of all oil and commercial gravel rights” includes an interest in natural gas.
2. Whether trade usage or other extrinsic evidence may expand “oil” in a recorded deed to mean oil and gas (or all minerals) when the deed does not mention gas.
3. Whether, given the construction of the 1944 reservation, the district court correctly resolved quiet title and related ownership claims affecting Mullinnix, LLC’s asserted interests.

## Decision

- The Wyoming Supreme Court affirmed the district court’s judgments in the consolidated appeals.
- The Court held the 1944 reservation of “oil and commercial gravel rights” did not reserve gas; gas title was properly quieted in the grantee-successors.
- The Court held informal industry usage evidence did not justify treating “oil” as including gas in a formal recorded deed where the deed language did not indicate that intent.
- Because Mullinnix’s claims depended on a gas-inclusive interpretation of the reservation and downstream conveyances from parties lacking gas title, the Court affirmed the rulings against Mullinnix.

## Legal Principles

- Deeds and mineral reservations are construed under contract-interpretation rules, beginning with the instrument’s language; unambiguous terms are enforced from the document’s four corners.
- Oil and gas are distinct mineral interests; “oil” in a reservation is not presumed to include gas absent clear indication in the instrument.
- Extrinsic evidence, including trade usage, may be considered to explain ambiguity but may not contradict or enlarge the clear scope of a formal, recorded deed.
- In resolving mineral title disputes, courts may weigh evidence of contemporaneous drafting practice (including how similar deeds specified “oil and gas”) when determining whether a claimed broader meaning is credible.

## Conclusion

The court enforced the 1944 reservation as written, limiting it to oil and commercial gravel and excluding gas, and it rejected attempts to use informal trade usage to broaden unambiguous deed language; as a result, quiet title determinations and related claims premised on a gas reservation, including Mullinnix’s asserted interests, were properly denied.


Mullinnix, LLC v. HKB Royalty Tr., 126 P.3d 909 (Wyo. 2006)