Of course you should get to the Abominable Fat Bike Race in Tomahawk Saturday, but biking in Harrison is probably done for the year. I went out to drag some trail tonight. It was a good workout, but I don't think it was too productive. The snow had some moisture and the hills set up well when I rode the sled down, but too much snow has accumulated on the lakes for a bike to be ridden off a beaten path.
Ice is 99.9% solid, but I did find a thin spot on Lake #7 near something rotten we'd ridden right over in January. The water was surprisingly warm and foul smelling. I didn't go in too far past my knees and was able to crawl out and head back the other way.
Harrison is now the domain of fat skis, snowshoes and the otter I saw on the hill between Lake #1 and Beaver Lake. Underdown should have a few more good fat bike weekends here and there this winter.