If you’re a troop in the Salt Lake area with scouts wanting to work on the Cycling merit badge, I hope you have found the Jordan River Parkway Trail. This paved non-motorized bike path follows the Jordan River from its headwater at Utah Lake 40+ miles northwards through Salt Lake County to I-215 where it meets the Legacy Parkway Trail in Davis County. 
There are only a few short sections that are incomplete and detours onto the street, but this bike trail is awesome and fun to travel for any length of ride your boys might be ready for.
My troop has done the JRPT several times using either of these approaches:
1. We’ve had designated drivers drop us off at a starting point, then pick us up at a designated ending point a few hours later.
2. We’ve parked at a trailhead and rode ½ way out and then back to where we started.
My only “complaint”, if you even want to call it that, is about the northern most end of this trail. If you wanted to start at the “beginning” of the JRPT near I-215 where the JRPT North Segment Section 1 map shows its start, you will not find a trailhead at that exact spot. In fact, the “official” trail point you see on that map is out in the weeds near the border between Salt Lake and Davis counties.
The first time we attempted to ride from the northern terminus, we didn’t find it! The Pony Express RV park right off I-215 at north Redwood Road is gated, blocking what we thought might be the actual starting point. Without giving it much thought, we pulled in to the closest connection to the trail we could find – which ended up being the parking lot of Salt Lake Imports on Redwood Road, just south of I-215. Luckily it was early Saturday morning and no one was around to care.
We were a lot smarter on the next trip and looked north of I-215 and found a much better starting point at the Center Street Trailhead (just west of Redwood Road in North Salt Lake – down the street from the Maverik station at 880 W Center St). For us, this starting point was the south end of the Legacy Parkway Trail but didn’t mind the extra 1.5 miles we had to pedal south (under I-215) before connecting with the official north end of the Jordan River Parkway Trail.
Here’s a Google Earth file of this trail system and all the places you can park and go. There are enough trailheads along this route that you can drop in anywhere to easily satisfy a 10, 15 or 25 mile ride requirement. You might even consider using this trail system for the 50-miler if you don’t want to or can’t ride around Bear Lake.
