Here are some corrected distances that I only guessed at in the previous post – thanks to Maps.google my guesses were close, but driving the route is lots better.
To get to the put-in from almost anywhere head north on US-29 from I-70, this close to Ellicott City. In about 1/2 mile US-29 comes to it’s northern end. Turn right on MD-99 and in about 0.7 mile take the 2nd exit from the ‘Round About’ onto Old Frederick Rd. After about 0.5 mile on Old Frederick Rd. turn left onto Daniels Rd. This will lead down hill into Potapsco Park where you will find a small parking area on the left at about 0.9 miles.
This evening to get the correct distances I drove down to the put-in, and since I had my camera with me you can see second hand what some of the river looks like: