View Tubing Monkton to Glencoe in a larger map
Directions to the Monkton Parking lot: Take exit 27 on 1-83. Head East on Route 137 Mount Carmel Road. Travel .6 miles. Take a right on York Road Route 145 going south. Travel one block. Take a left on Monkton Road, Route 137 heading east. Travel another 3 miles. At the bottom of the long hill you will see the river, the train station and the parking lot, as well as the tube rental store.
This year I decided to make a tubing trek from Monkton to Glencoe a Mountain Club of Maryland trip so I could get some more detail and pics for all of you who have interest. I didn't do much to advertise this event and only one kind soul showed up to go with me. After making these big plans to get better pics, I ended up leaving my dry bag and good camera at home. So these fuzzy low-resolution pictures taken with my PDA will have to suffice. My apologies!
I had never tubed from Monkton to Glencoe although I have tubed several other stretches of the river. Luckily we had much rain recently and somebody decided to open up the gate up at Pretty Boy so the Gunpowder was flowing fairly fast. The river was still pretty shallow though so we didn't need to worry about drowning.
My cohort, Ellen, rented a tube at Monkton Bike Rental, it was a truck inner tube with a really nice cover on it as well as a mesh bottom. Ellen is a MCOMD member who recently moved here from Tucson.
The Gunpowder water was cold as usual. A bird followed us down river and Ellen managed to get herself bit not once, but twice in the same area of her elbow by bees. Her arm puffed up a bit but we were having too much fun to be concerned. I hope she doesn't end up in the hospital tonight. 
The river twisted and turned, it took us about 3 hours to get down to Glencoe. We returned to Monkton via the NCR trail.
UPDATE June 2008 For another post about tubing on the Gunpowder River at Big Falls, north of Monkton click on this link I've got directions, map and video for you.