Dry Waterfall and Two Pines Arch
Look closely (you may need to enlarge this) a bit to the left of the large red outcrop and spot the arch. Continue up the watercourse a bit and then head for the arch.
To go on to Progeny Peak's summit, ascend the ramps and outcrops shown to the left of the arch. Here, the route gets into Class 3, maybe some 4, and it is the only real scrambling along the route.
Zion National Park, Utah-- April 2014