Utah court on mile markers, Harry Potter, and marijuana

Kathryn Rubio (Above The Law) spotted this item in a Utah Supreme Court case from last week, Barneck v. Utah Dep't of Transportation (written by Justice Thomas Rex Lee, the brother of U.S. Senator Mike Lee and son of Rex Lee, who had been U.S. Solicitor General under President Reagan):

On a July afternoon in 2011, over an inch of rain fell over the course of about an hour in the area near mile marker 46[1] on SR-35 in Duchesne County.

[Footnote 1:] The briefs identify this area a bit differently. They refer to it as "near mile marker 46.5." We are unsure of what to make of that formulation, as we suppose that a "mile marker" is in fact a mile marker and not a half-mile marker, and see no indication in the record or elsewhere that UDOT uses half-mile markers. But we note this discrepancy anyway. We do so in case there literally is a "mile marker 46.5" on SR-35. Cf. J.K. Rowling, Harry Potter and the Sorcerer's Stone 89-90 (1998) (noting Uncle Vernon and Aunt Petunia's disbelief in the notion of a Platform 9 3/4 at King's Cross Station); John Ingold, Colorado Hopes a Mile 419.99 Sign on Interstate 70 Thwarts Stoners, Denver Post (Jan. 10, 2014), http://www.denverpost.com/news/ci 24889289/colorado -hopes-mile-419-99-sign-interstate-70 (noting the replacement of mile marker 420 on 1-70 with marker 419.99; noting that the number 420 is "[i]n sports terms," the "'Roll Tide' of weed," and explaining that marker 420 repeatedly had been stolen by "marijuana enthusiasts") (Only in Colorado. Or so we assume.)