Beginning at the main visitor center immediately inside the park entrance this out and back paved ride is a must do for a tandem team. The round trip 16 mile trek takes you through the heart of Zion National Park, and during the summer, along a road open only to the occasional shuttle bus.
At nearly 4,000 ft elevation the ride begins with 1.5 miles along a meandering and paved bike trail. Open to pedestrians it is a good warm-up and cool-down section. Many forms of wildlife are readily visible (in our run at it we passed a full size tarantula!).
After crossing under highway 9 the bike path exits onto Zion Canyon Scenic Drive. From this point on your only worries will comprise of watching for wildlife (we spotted wild turkeys, toads, deer, and hawks), identifying those one of a kind photo opportunities, and allowing the occasional tour shuttle to pass (only 1 did so during our ride up).
The ascent to the back of the park is gradual and steady. Along the way there are a number of restrooms and pull outs. This ride is more about the scenery than testing your physical prowess but the ride back down is a suitable reward also. Upon reaching the turn around you can pretty much allow gravity to do the rest as you descend back to the visitor center (just remember the 35 mph speed limit counts for bikes too).