UNITED STATES COURT OF APPEALS 

FOR THE TENTH CIRCUIT 

_________________________________ 

MICHAEL L. MACGOWAN, JR., 

 Plaintiff - Appellant, 

v. 

TOWN OF CASTLE ROCK; JASON 

GRAY, Mayor; TARA VARGISH, 

Director, 

 Defendants - Appellees. 

No. 22-1061 

(D.C. No. 1:21-CV-01246-RM-MEH) 

(D. Colo.) 

_________________________________ 

ORDER AND JUDGMENT*

_________________________________ 

Before TYMKOVICH, PHILLIPS, and EID, Circuit Judges. 

_________________________________ 

Plaintiff Michael L. Macgowan, Jr., proceeding pro se, sued the Town of 

Castle Rock, Colorado and two Castle Rock officials for alleged civil rights 

violations relating to the Town’s denial of his application for a zoning variance. The 

district court dismissed the lawsuit and Mr. Macgowan has appealed. Exercising 

jurisdiction under 28 U.S.C. § 1291, we affirm. 

* After examining the briefs and appellate record, this panel has determined 

unanimously to honor the parties’ request for a decision on the briefs without oral 

argument. See Fed. R. App. P. 34(f); 10th Cir. R. 34.1(G). The case is therefore 

submitted without oral argument. This order and judgment is not binding precedent, 

except under the doctrines of law of the case, res judicata, and collateral estoppel. It 

may be cited, however, for its persuasive value consistent with Fed. R. App. P. 32.1 

and 10th Cir. R. 32.1. 

FILED 

United States Court of Appeals 

Tenth Circuit 

November 23, 2022

Christopher M. Wolpert 

Clerk of Court

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I. Background 

 Mr. Macgowan seeks to erect a digital billboard next to an interstate highway 

within the Town’s limits. In 2018 he applied for zoning variances to accommodate 

his plans. The Town denied his request under a provision of the Town’s code 

prohibiting off-premises advertising. Mr. Macgowan then sued the Town and its 

former mayor asserting violations of his rights under the First, Fifth, and Fourteenth 

Amendments. The district court dismissed the claims for failure to state a claim 

upon which relief can be granted. Macgowan v. Town of Castle Rock, Colo., 

No. 1:19-cv-01831, 2020 WL 127978 (D. Colo. Jan. 10, 2020). 

 In February 2021, Mr. Macgowan again requested a variance for his proposed 

digital billboard, which the Town denied on the same grounds as his previous 

request. He then sued the Town again for violations of his First, Fifth, and 

Fourteenth Amendment rights. In addition to the Town, Mr. Macgowan sued the 

current mayor of Castle Rock and the Town’s building director. 

The defendants moved to dismiss under Rule 12(b)(6) of the Federal Rules of 

Civil Procedure. They asserted, among other things, that the doctrine of claim 

preclusion prevented Mr. Macgowan from litigating the same constitutional claims 

that had previously been dismissed. The magistrate judge agreed and recommended 

dismissal, and the district court upheld that recommendation over Mr. Macgowan’s 

objection. This appeal followed.

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II. Discussion 

A. Standard of Review 

We review a dismissal under Rule 12(b)(6) de novo. Smith v. United States, 

561 F.3d 1090, 1098 (10th Cir. 2009). We accept as true all well-pleaded factual 

allegations and view them in the light most favorable to the plaintiff. Id. “The 

court’s function on a Rule 12(b)(6) motion is not to weigh potential evidence that the 

parties might present at trial, but to assess whether the plaintiff’s complaint alone is 

legally sufficient to state a claim for which relief may be granted.” Sutton v. Utah 

State Sch. for Deaf & Blind, 173 F.3d 1226, 1236 (10th Cir. 1999) (internal quotation 

marks omitted).1

B. Claim Preclusion 

 The district court dismissed Mr. Macgowan’s lawsuit under the claim 

preclusion doctrine, which “prevent[s] a party from litigating a legal claim that was 

or could have been the subject of a previously issued final judgment.” Lenox 

MacLaren Surgical Corp. v. Medtronic, Inc., 847 F.3d 1221, 1239 (10th Cir. 2017) 

(internal quotation marks omitted). The elements of claim preclusion are: 

“(1) a final judgment on the merits in an earlier action; (2) identity of parties or 

privies in the two suits; and (3) identity of the cause of action in both suits.” Id.

(brackets and internal quotation marks omitted). 

1

 Because Mr. Macgowan proceeds pro se, we liberally construe his filings, but 

we do not assume the role of advocate. Yang v. Archuleta, 525 F.3d 925, 927 n.1 

(10th Cir. 2008). 

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 We agree with the district court that the circumstances of this case satisfy all 

three elements of claim preclusion. Indeed, with respect to the first two elements, 

Mr. Macgowan makes no attempt to dispute that there was a final judgment on the 

previous claim and that the defendants are either identical to or in privity with the 

defendants in the prior case. 

 As to the third element, Mr. Macgowan appears to argue that there is no 

identity of the cause of action in both lawsuits. We have adopted the “transactional 

approach” to defining a “cause of action.” Nwosun v. Gen. Mills Rests., Inc., 

124 F.3d 1255, 1257 (10th Cir. 1997). “Under this approach, a cause of action 

includes all claims or legal theories of recovery that arise from the same transaction, 

event, or occurrence. All claims arising out of the transaction must therefore be 

presented in one suit or be barred from subsequent litigation.” Id. What constitutes 

“the same transaction” must be “determined pragmatically, giving weight to such 

considerations as whether the facts are related in time, space, origin, or motivation, 

whether they form a convenient trial unit, and whether their treatment as a unit 

conforms to the parties’ expectations or business understanding or usage.” Hatch v. 

Boulder Town Council, 471 F.3d 1142, 1149 (10th Cir. 2006) (internal quotation 

marks omitted). 

We are satisfied that the instant lawsuit involves the same causes of action as 

his previously dismissed lawsuit. In each case, Mr. Macgowan submitted essentially 

the identical request to the Town concerning his proposed digital billboard and 

received the identical response. In both lawsuits, he raised claims under the First, 

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Fifth, and Fourteenth Amendments to challenge the Town’s denial of his request. 

Mr. Macgowan argues that his second lawsuit is not the same cause of action because 

he identified a specific Town ordinance that he had not identified in the first lawsuit. 

But a more specific citation of authority in support of the same claims is insufficient 

to avoid claim preclusion. 

III. Conclusion

 For the foregoing reasons, we affirm the decision of the district court. 

Entered for the Court 

Gregory A. Phillips 

Circuit Judge 

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