Susan Davis Van Dyke v. the Navigator Group, 647 S.W.3d 901

In a 1924 deed Geo. H. Mulkey conveyed land to G.R. White and G.W. Tom while reserving "one-half of one-eighth of all minerals and mineral rights." The parties dispute whether that reservation equals 1/16 or a different share.
Mulkey Assignees (heirs/assigns of the Mulkeys) claim the reservation yields one-half of the minerals; White Assignees claim the reservation is a double fraction equal to one-sixteenth, leaving 15/16 conveyed.
The trial court granted summary judgment for White Assignees, holding the deed unambiguous and reserving 1/16 to the Mulkeys; other dependent claims were severed.
On appeal Mulkey Assignees argued (1) the estate misconception doctrine should inform construction to yield a 1/2 share, (2) the presumed-lost-deed (presumed grant) doctrine established a 1/2 interest, and (3) equitable/judicial estoppel and related defenses precluded summary judgment.
The court reviewed deed construction de novo, concluded the reservation is unambiguous as a "fraction of a fraction," held surrounding historical misconceptions cannot create ambiguity, and ruled presumed grant cannot change an unambiguous deed; estoppel defenses were not preserved to defeat the deed-construction summary judgment.
The Eleventh Court of Appeals affirmed the summary judgment declaring the Mulkeys reserved 1/16 of the minerals and White/Tom received 15/16.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Deed construction: meaning of "one-half of one-eighth" reservation	Mulkey Assignees: ambiguous; should be read to reserve one-half of minerals	White Assignees: unambiguous double fraction = 1/16 reserved; 15/16 conveyed	Court: unambiguous; reservation is 1/2 of 1/8 = 1/16; affirm summary judgment
Estate misconception theory as an aid to construction	Mulkey: historical assumption about 1/8 royalty shows parties intended 1/2 ownership	White: cannot use historical misconception to override plain, consistent deed language	Court: cannot use that theory to create ambiguity where deed is clear; doctrine not dispositive
Presumed lost deed / presumed grant to alter quantum of interest	Mulkey: long acquiescence and documents imply a lost conveyance returning 7/16 to Mulkeys so they hold 1/2	White: chain-of-title and 1924 deed are clear; presumed grant inapplicable to change deed's express terms	Court: presumed grant cannot be used to change the clear terms of the deed; no fact issue entitling Mulkeys to 1/2
Equitable/judicial estoppel defenses	Mulkey: recitals in later deeds and probate inventories estop White from claiming >1/2	White: defenses were not adequately presented to defeat deed-construction MSJ; moved only on certain estoppel theories	Court: estoppel defenses not properly raised/preserved to defeat MSJ; any trial-court error in granting no-evidence SJ on those defenses was harmless

Valence Operating Co. v. Dorsett, 164 S.W.3d 656 (Tex. 2005) (de novo review of deed/mineral-rights construction and summary-judgment principles)
Hysaw v. Dawkins, 483 S.W.3d 1 (Tex. 2016) (estate-misconception doctrine may inform but does not override clear instrument language)
URI, Inc. v. Kleberg Cty., 543 S.W.3d 755 (Tex. 2018) (objective intent and four-corners interpretation control contract/deed construction)
Luckel v. White, 819 S.W.2d 459 (Tex. 1991) (harmonizing conflicting fractional provisions in mineral conveyances)
Concord Oil Co. v. Pennzoil Expl. & Prod. Co., 966 S.W.2d 451 (Tex. 1998) (resolving inconsistent fractions in deeds; harmonization approach)
U.S. Shale Energy II, LLC v. Laborde Props., L.P., 551 S.W.3d 148 (Tex. 2018) (distinguishing fixed vs. floating royalty language and limiting reliance on typical 1/8 royalty absent deed language)
Kachina Pipeline Co. v. Lillis, 471 S.W.3d 445 (Tex. 2015) (surrounding circumstances cannot be used to manufacture ambiguity)
Graham v. Prochaska, 429 S.W.3d 650 (Tex. App.—San Antonio 2013) (treating simple fractional reservations as fixed interests when instrument is clear)
Garrett v. Dils Co., 299 S.W.2d 904 (Tex. 1957) (judicial notice that one-eighth was a common royalty standard in the era)