Well, so I followed my own advice, and emailed the station. Bad news, but not unexpected...
Here is their reply:
The FCC has just granted KMAX a construction license for its HD transmitter
tower. The building construction will begin soon and the tower will be
installed at the beginning of 2003. I'm not sure when KMAX will begin
broadcasting in HD...the deadline is 2006. And, you are correct in the
channel designation being Channel 21. Thank you for watching UPN 31.
Sent: Thursday, April 11, 2002 3:21 PM
Subject: Request about Promotion & Contests
From Donald Hearth
About Promotion & Contests
Could you tell me when your High Definition channel (I believe that it is
Channel 21) will be ready for broadcasting?
I know that UPN does not currently have HDTV programs, but I would like to
have at least 480i broadcast quality while watching the Kings, Enterprise,