While I mentioned earlier that Madison's WHA started in 1954, I didn't say anything about the rest of what's now Wisconsin Public Television: The remainder of the full-power WPT stations didn't sign on until the '70s (with Green Bay's WPNE apparently being the first to do so). Even now, Green Bay is a larger TV market than Madison.
...in fact, WPNE/38 was originally planned to be WRST-TV, licensed to the University of Wisconsin-Oshkosh. Politics between the Green Bay and Oshkosh campuses eventually led to the Green Bay campus taking over both the TV station CP and what was then WHKW-FM Chilton, a satellite station of WHA Radio in Madison...
In addition, WHA may have, on occasion, had some different programming from the rest of WPT. At the very least, I don't think WHA's "Saturday Morning" lineup of old TV shows (e.g., "Alfred Hitchcock Presents") during the '80s was carried by any of the other WPT stations.
Also, Wisconsin is an interesting situation in that Milwaukee's aforementioned WMVS and WMVT have some ties with WPT--but have always been operated outside of it. (The same goes for Duluth/Superior's WDSE.)
...WHA-TV was licensed to the University of Wisconsin, separate from the other WPT stations which were licensed to the Wisconsin Educational Communications Board. Thus, even when simulcasting most of its programming with WPT, WHA-TV was officially a separate entity in the '70s and '80s. WMVS and WMVT are owned by Milwaukee Area Technical College, and WDSE is owned by Duluth-Superior Area Educational Television Corporation (which also owns and operates WRPT/31 Hibbing), also separate entities...