Your 0.3-mile fire-road climb on Tree Frog Loop will involve about 250 feet of elevation gain, implying a painful overall average grade of over 16%, and there are several spots on the climb where the grade temporarily exceeds 20%. In the end, though, this is still a short climb that can just as easily be walked.
At the top, the singletrack portion of Tree Frog Loop branching off to the left signifies your arrival at the second flow trail on the ride (which I've also seen named separately as "Peregrin Trail"). You actually need to pedal for nearly the first quarter mile of this stretch, but then the fun descent begins and doesn't end for 2.5 miles as you connect to Rumsen Trail along the way and continue on that to its end. There are a couple more stretches along the way where you need to pedal, but no real climbs. This descent is very similar to Sugar City Trail in terms of speed and character, but it's longer, goes through significant tree cover in a number of places, and features better banked hairpin turns, as far as I'm concerned. There was one thing about this descent that bothered me, though: the trail was off camber at a number of places and sloped downhill on many flat sections. I fear that this doesn't bode well for its sustainability, especially in those places where it takes a quick dip followed by a sharp rise, where the speed gained during the dipping part makes it harder for the rider to follow the curve on the off-camber rising part, tending to force one off the downhill edge of the trail and resulting in a trail that will slide downward in the long run. A couple of turns were already showing signs of this during my ride, only a few months after the construction of the trail.