I found the best way to ride this trail is from the parking area at its lowest point - along the north fork of the South Platte River. By parking here you'll have driven past Reynolds Park which is the high point of the ride.
From the parking lot, you'll start a mellow climb through scattered ponderosa pine and an abundance of pretty much every type of wildflower in the state (when I went early July). The trail is a rolling climb for the first 7 or so miles - a couple hundred ft. up, then 100ft down - you'll come to some doubletrack for about 1 mile then the trail branches back off and continues to climb.
At approximately mile 8, you start a longer downhill into Reynolds Park. Continue to the intersection of Hummingbird Trail
and take a left to start a fun and fast 1 mile descent to South Foxton Road.