I woke up to several emails in by box from a Yahoo Group I belong to, WisconsinWX, started by a post from Greg in Elcho (above). I did a quick search online but found no information or reports concerning this sighting.
I've never witnessed something that I'd call a UFO, but I think it's a fun topic, so I was interested to find an entire website to UFO reports in Wisconsin, both recent and historical.
From my area in far northern Wisconsin there seems to be a pretty comprehensive report from reliable sources dated 13 March 1975, supposedly reported in the Rochester Post-Bulletin on 20 March 1975. Here's a copy/paste of that report with a drawing (below) from the website with pictures:
Wisconsin Officers Report Multiple Sightings of UFOs (Mar 1975).
Ashland, WI (AP) - Authorities in a four-county area of Northern Wisconsin have reported several recent sightings of unidentified flying objects, with nine deputies in Ashland and Iron counties saying they saw four UFOs at one time.
At the time of the sightings, officials said, police radios were garbled or went out of service and witnesses said they saw the objects moving, changing colors, and heading toward a common position in the sky.
Authorities at the nearby Duluth airport said there was no radar contact made at the time, late in the evening of March 13.
Ashland County Sheriff Joe Croteau said "telephones were ringing off the hook from citizens who also saw the objects". Sightings were also reported in Douglas and Price counties.
A rural Mellen resident, Mrs. Phil Baker and her daughter, Jane, 15, told authorities "an object" landed on a road near their home, made noises and high-pitched sounds, and had red and green lights around it.
Ashland County Undersheriff George Ree, who investigated, said he found no evidence of a landing. He left their home and drove about two miles to meet with deputies. Then, he said, he and the deputies saw four UFOs, one brighter than the others. They said the brightest one moved, changed colors, and then became stationary while three smaller objects headed toward it.
Pictures concerning the people in this report and more information from the History Channel can be found through this link. The pictures could be a hoax, I couldn't say one way or the other.