The Farmington River between Satan's Kingdom and Collinsville has deeper water than other section and so it is runnable in dryer periods. There are mainly sections of Class II rapids with one Class III+ in the Satan's Kingdom gorge. A portion of this trip is used by a river tubing concession in summer.
Launching from the parking area at Satan's Kingdom, the rapids begin immediately with a nice II section beginning under the Route 44 bridge. The river then enters the gorge. The III+ rapid is near the end of the gorge and features a huge bolder that blocks an easy exit from the rapid. It is possible to carry on the right bank but be prepared to walk on large boulders to get around. One can view the gorge from the Route 44 bridge to get a view of the rapids.
After the gorge, there is another nice stretch of II's within Nepaug State Forest. The river then has nice calm stretches with mainly Class I's before reaching the tubing concession take out on the left along Route 44. The trip continues with quickwater and class I's as it winds along in an unspoiled area. The last set of rapids is by the old black bridge> after that, the river enters the slackwater of the Collinsville Dam. It can be a long paddle here in a white water boat.
We did this section in a Prijon Invader and Perception Axess in about two hours. I flipped in the Invader, could not roll and had to do a wet exit.
Plenty of parking at the launch and take out.
Satan's Kingdom is on Route 44 in New Hartford. The takeout is on Route 179, next to Collinsville kayak shop.