KAPP-KVEW (Apple Valley News Now, ABC) in central WA. No newscasts at all on weekends, and it has been that way for over 15 years. Syndicated programming airs at 11pm on Saturday and Sunday.
For many years, there was NO local news on weekends on any Yakima TV station. For the entirety of the '90s, there was no weekend news on KIMA. They were one of the last affiliates to run the CBS Sunday Night News on-time with the network feed, even in the final months with Russ Mitchell (at 11PM PT). It looks as though WCAX in Burlington was one of the (very) few others. Saturdays were all syndicated programming after primetime and until sign-off. There was a time when CNN Headline News aired at 11PM.
KNDO went from NBC's Sunday movie directly to George Michael Sports Machine at 11pm, between 1991-1998. Saturdays had a half-hour of NBC Nightside before SNL via the eastern time feed. Prior to that, they aired Marvin Scott's USA Tonight (INN).
KAPP aired the ABC News Weekend Report on-time with the network, then went to infomercials or the 700 Club on Sundays, usually Gunsmoke or a movie on Saturday at 11:15. Beginning in 1991 they had Saturday news, and added Sunday news in 1997.
Until recently, KXLY Spokane had no news on Saturday (but did have 11pm news on Sunday night).