Put in at Rend Bridge which is roughly 5 miles east of Ramsey, IL. Putting in there is always fun. There is a fresh water spring that flows from a small bluff. Part of the spring is piped down the bluff and people fill water jugs there.
This river is great for beginners and/or causal float trips. The river is deep for this part of Illinois and it is wide. Navigation is a breeze on the this part of the river. Stringers are kept to minimum and easily maneuvered around.
My buddy and I did not float; we went at a pretty good pace. We got out at Vandalia at the boat ramp. This is a 24.75 mile trip. With a few short breaks to stretch and eat the trip took 6.5 hours. If you are looking for a shorter trip there is a county road that would cut the trip down to roughly 10 miles.
Spring water at the beginning then nothing.
From Vandalia take 51 north to Ramsey at Miller's Grocery store turn east. Approximately 5 miles later you will see the river. The ramp and spring are on the west side of the bridge on the south side of the road. Look for the cross or signs for the cross.
Google Earth and USGS Water Watcher