Denver, CO - Nothing.
Special Retro - 98.3 was the frequency of KFMZ in Columbia, Missouri (where I spent a good part of the earlier days of my life), a station that lost its license in 2001 due to the shenanigans of the principal owner of Contemporary Media. That frequency was blank for some years, with EMF eventually putting a translator on the channel. That, in turn, was bumped after the FCC auctioned off the license to the frequency to a new applicant, which began operations in 2016 as KDVC, "The Dove".