In Kisor v. Wilkie, 139 S. Ct. 2400 (2019) ("Kisor"), this Court sought to limit Auer deference and provided specific guidance for courts to interpret regulations, consistent with footnote 9 of Chevron. The fundamental issue underlying this petition is whether the D.C. Circuit misinterpreted and therefore misapplied Kisor by using the "traditional tools" of construction to create ambiguity and support the agency's position, rather than using the "tools" to dispel ambiguity and apply the regulation as written. Despite a specific "15-month" look-back rule in 30 C.F.R. §100.3(c), for determining a mine operator's violation history, the D.C. Circuit granted deference to the Secretary of Labor's inclusion of violations older than 15 months, due to perceived ambiguity. The improper use of the "tools" of construction to create ambiguity expands Auer deference in administrative cases, with significant adverse implications for independent judicial review. The questions presented are:

1. Whether the Court should overrule Kisor or clarify that the "traditional tools" of construction must be used to dispel ambiguity in a regulation, rather than to create ambiguity and find support for an agency interpretation—a matter on which there is a conflict among the Circuit Courts.

2. Whether, under a proper application of Kisor, 30 C.F.R. §100.3(c) precludes the consideration of violations occurring before the specified "15-month" look-back period for determining a mine operator's "[h]istory of previous violations," to ensure the regulation is not expanded beyond its terms.

Whether the Court should overrule Kisor or clarify that the 'traditional tools' of construction must be used to dispel ambiguity in a regulation, rather than to create ambiguity and find support for an agency interpretation