There are no unsupported FKT efforts on this route so I thought I'd set the bar low. It was not the fastest time, not a fast time at all, but it is the Fastest Known Time- in one specific category. Also, epic.
First 10 miles super slow and draining in the sand in the La Verkin Creek valley. Filled three bottles (1.5 liters) at Beatty Spring (mile 7), flowing fast.
Then the trail turned to dirt as it climbed via Hop Valley trail and then on to the Connector trail the to the White Rim trail where it levels off a bit. Was lucky to see two backpackers filtering water around mile 21 or I would have missed it and had a much longer day (not sure if it was Wild Cat Spring or some other spring). I downed a liter and refilled the bottles then continued on Wild Cat trail. Best part of the day running up high above the canyons.
Heard there was water at Cabin Spring at mile 32 so was drank up my bottles. Cabin Spring was off trail and hard to find, and was barely dripping. Water was also pretty dirty. Took a few ounces through the filter then decided to go the last 5 miles into Zion Canyon with no water.
Ran down the last 5 miles in about 90 degree heat, steep and concrete and holiday weekend crowded. Took a swim in the Virgin River after I finished then fought my way onto a packed shuttle. Ate 2 pb and j's, two Maurten caffeine gels and two homemade giant Pedro's Carbarita gels. Drank about 4 liters of water. 7:45 elapsed.