All conjecture, but the track does look like LOC 23 may have been the approch considered. Distance past the airport is consistent with flightaware.com/resources/airpor … DME+RWY+23
Pilot would do a procedure turn or be vectored to do a UB turn to interecept the localizer.
Or he could have planned a diversion. Many choices…
Looking at weather at weather.gov/data/obhistory/KMRB.html (closest NWS weather reporting)
It looke to me it was prime time icing conditions, so again conjecture on my part that may have been a factor.