Milus v. Sun Valley Company: Clarifying the Standard of Care and the Assumption-of-Risk Bar under Idaho’s Ski Area Liability Act

Introduction

On 25 June 2025 the Idaho Supreme Court issued its substitute opinion in Milus v. Sun Valley Company, Dkt. No. 49693-2022, a wrongful-death case arising from a tragic skiing accident at the Sun Valley Resort in 2019. The core dispute concerned the interpretation of Idaho’s Responsibilities and Liabilities of Skiers and Ski Area Operators Act, Idaho Code §§ 6-1101 et seq. (“Ski Area Liability Act” or “the Act”). Specifically, the Court tackled two long-debated questions:

What standard of care binds ski area operators when carrying out the nine statutory duties listed in § 6-1103(1)–(9)?
How does the assumption-of-risk provision in § 6-1106 interact with a skier’s negligence claim premised on alleged statutory violations?

The opinion not only resolves those questions, overruling decades of uncertainty created by a 1990 plurality in Northcutt v. Sun Valley Co., but also re-balances the relationship between operator obligations and skier responsibilities. Although the Court ultimately affirmed summary judgment for Sun Valley, it did so on refined legal grounds that will govern future litigation statewide.

Summary of the Judgment

Standard of Care. Operators are held to an ordinarily prudent person standard when performing the nine enumerated duties in § 6-1103. The statutory carve-out in § 6-1103(10) removes any standard of care only for voluntary, additional activities—not for the duties mandated in subsections (1)–(9).
§ 6-1103(2) Claim (Marking Equipment). While the district court mis-categorized the issue as one of duty instead of breach, the yellow padding on “Snow Gun 16” was undisputed evidence of a “warning implement.” Milus produced no contrary evidence; thus no triable issue existed.
§ 6-1103(6) Claim (Top-of-Run Notice). The Court broadened the statutory phrase “snowmaking operations are being undertaken,” holding it applies whenever equipment is in place and capable of operation—not merely when snow is actively blowing. Consequently, a jury question exists as to whether Sun Valley actually posted a conspicuous notice at or near the top of the Lower River Run.
Assumption of Risk (§ 6-1106). Despite the jury question on notice, the Court affirmed dismissal on the alternative ground that § 6-1106 bars recovery where the skier’s injury arises from plainly visible or plainly marked snowmaking equipment. Because Snow Gun 16 was “plainly marked” within the meaning of § 6-1103(2), Mr. Milus assumed the risk as a matter of law.
Attorney Fees. No party prevailed entirely on appeal; Sun Valley’s request for fees under § 12-121 was denied.

Analysis

A. Precedents Cited

1. Northcutt v. Sun Valley Co., 117 Idaho 351 (1990)

Northcutt’s two-justice plurality had suggested that § 6-1103(10) abolished any standard of care for the statutory duties. Because only a plurality adopted that view, its precedential value was always shaky. Milus explicitly disavows Northcutt’s reading, restoring a standard-of-care analysis.

2. Long v. Bogus Basin Recreation Ass’n, 125 Idaho 230 (1994)

Cited by Sun Valley to resurrect the Northcutt rationale, Long actually focused on whether a plaintiff met the statutory definition of “skier”; it never held that no standard of care applies to statutory duties. Milus clarifies this historical misunderstanding.

3. Withers v. Bogus Basin Recreation Ass’n, 144 Idaho 78 (2007)

Withers addressed inherent risk collisions under § 6-1106, but its dicta about eliminating the “common-law standard” is now confined to inherent risk claims, not statutory duty claims. Milus curtails any over-reading of Withers.

4. Davis v. Sun Valley Ski Educ. Found., 130 Idaho 400 (1997)

Recognized that § 6-1106 creates a legislative assumption-of-risk defence that supersedes comparative fault under § 6-801. Milus relies on Davis to hold that the defence bars otherwise viable negligence claims.

5. Comparative Fault Cases (Salinas v. Vierstra, Rountree v. Boise Baseball)

The Court distinguished the general abolition of assumption-of-risk from § 6-801 by acknowledging that the Legislature may carve out specific statutory exceptions—exactly what § 6-1106 does.

B. Legal Reasoning

Textual Interpretation of § 6-1103(10).
- The Court parsed the three subordinate clauses of subsection (10) and held that the no-standard provision applies only to additional activities voluntarily undertaken.
- This reading preserves the operative effect of subsections (1)-(9) and avoids rendering them “mere surplusage.”
Return to Common-Law Negligence Structure. Once the duty exists, breach is judged against the “ordinarily prudent person” in the circumstances. The district court erred in labeling the adequacy of yellow padding as a duty question (legal); it was in fact a breach question (factual). Yet the plaintiff still lost because no competing factual evidence was produced.
Broad Construction of “Snowmaking Operations.” Linguistically, “operations” embraces the entire operational posture, not merely active snow discharge. This interpretation protects skiers who must react to fixed equipment even when idle.
Operation of § 6-1106 as an Affirmative Defence. a. The first clause lists specific inherent risks assumed by skiers, including collisions with plainly marked snowmaking equipment.
b. Because Snow Gun 16 satisfied § 6-1103(2)’s marking requirement, the equipment fell squarely within the assumption-of-risk bar.
c. Invoking Davis, the Court explains that § 6-1106 implicitly amends comparative-fault law for skiing cases; once the defence applies, recovery is completely barred.

C. Likely Impact of the Decision

Legal Clarity. Trial courts can now confidently apply an ordinary-prudence standard to alleged breaches of § 6-1103(1)–(9), ending decades of confusion fostered by Northcutt.
Operator Practices. Resorts must reassess safety protocols, signage, padding, and patrol standards with an eye toward what a reasonably prudent operator would do—not merely the bare statutory minimum.
Plaintiff Strategy. Claimants must marshal concrete evidence of breach (e.g., expert opinions on adequacy of markings) to survive summary judgment; merely disputing legal duty will no longer suffice.
Assumption-of-Risk Litigation. Defense counsel will rely heavily on § 6-1106’s enumerated risks. Plaintiffs will focus on proving either (a) the equipment was not “plainly marked,” or (b) the injury arose from a risk not listed in the statute.
Legislative Pressure. The dissent underscores policy concerns about having no standard of care for voluntary safety measures. Legislators may revisit § 6-1103(10) to codify a specific standard—or to adopt the Court’s reading statutorily.

Complex Concepts Simplified

Ordinarily Prudent Person Standard: The benchmark used in negligence law: “What would a reasonably careful person do under similar circumstances?”
Statutory Duty vs. Common-Law Duty: A statutory duty is created by legislation; common-law duty arises from judicial precedent. Here, the nine tasks in § 6-1103 are statutory duties.
Assumption of Risk (Primary): When a participant knowingly encounters a hazard that is inherent to an activity, the law may bar recovery entirely. Section 6-1106 codifies this defence for skiing.
Summary Judgment: A procedural device allowing a court to decide a case without trial when no genuine dispute of material fact exists.
Plainly Visible or Plainly Marked: If a hazard is obvious (visible) or is clearly indicated by signage or padding (marked), it falls under the assumption-of-risk umbrella.

Conclusion

Milus v. Sun Valley Company recalibrates the balance of obligations between Idaho ski resorts and their patrons. The Court revived the ordinary-prudence benchmark for statutory duties, while simultaneously reinforcing the powerful shield that § 6-1106 provides to operators when injuries stem from obvious, well-marked hazards. Plaintiffs will now shoulder a twin burden: establish both a breach of prudent practice and facts removing the accident from the statute’s assumption-of-risk catalogue. Operators, for their part, must treat statutory duties as minimum obligations executed with reasonable care, lest they forfeit the immunity they seek to claim. The decision thus stands as a pivotal reference point for all future ski-related tort litigation in Idaho and offers a roadmap for other jurisdictions wrestling with similar recreational-liability frameworks.