The Apple River from the Black brook Dam to Star Prairie is a fun paddle. This is 15 miles or so above the area with all the tubers by Somerset. The first Section from Black brook Dam to High bridge is full of class I to II rapids, a super fun paddle but there are 2 small water falls I portage around that can be run easily. There are constantly changing conditions with downed trees blocking the river here. Last year I cleared several spots with on an all "tree guys with chains saws" trip. But I have not done that yet this year. The end of this section is calmer with more places to fish and that continues into the next section from High bridge to Church Road. From Church Road to Star Prairie there are some more Class I rapids and you will see more people here.
Jon
PS running a chainsaw from a canoe that is floating up against a logjam is tricky and when the drinking starts it gets really crazy.