How big a boat will fit through there? I could not find any info on the Dam Operation.

If I had to guess 50'

The River Shiver boating event used have about 50 boats going through the dam. Not sure what the largest boat was but I would guess Mike Lovergines 42 fountain.

Do you really want to run the lower river from Mchenry to Algonquin?? I used to run that stretch, but after hitting submerged things or being forced too go close to shore and then run aground, I have never gone back down there. IMO it is for small boats and ski type boats.

Hey Mark, I was able to get my 42 Sonic through with plenty of room, and there is enough space to get 2 boats side by side with 8 1/2 beams. Be careful on the lower river you do not want to get outside of the buoys.

So there are bouy's to stay in between...oh boy,
I like the ramps at the Fox River Preserve mid way down from the locks.

The lower part of the river is a fun place to go however; there are many things to consider before you make the journey.

1) Did it rain before your trip…?
a. If yes… you need to watch out for floating timber.
b. If no… Water levels maybe an issue. Lower water conditions would not be a good time to attempt.
2) Buoy Makers
a. Stay within each never stray outside of a green or red marker…Water level drops to 1 foot or less in certain areas if not in center of channel
b. Watch out for the family tubers and skies in the tight narrow stretches of the river. Why people pull their kids in a very narrow stretch of the river is still a mystery to me.
3) Return Time considerations.
a. Have waited for three hours (+) at the Dam to get back to the Upper Lake. Not fun in 90 degree plus weather.

All in all the entire lower river is a great adventure. Just be careful.

3 Hours...holy crap!
Thanks for the info Bob.

No problem. Hopefully, summer will be here soon and we can get on the water.

Can't wait!