The first 16 miles: the hilly half that sets up your day
The opening 16 miles are the part with teeth. This loop shares the 16 mile course and stacks up most of the climbing, so it is where you bank or blow your race. The hills are the rolling foothill kind, repeated rollers rather than one giant climb, and the trap is treating them like flat ground because none of them looks huge on its own. Hike the steeper pitches, keep your effort even, and get through the first half feeling like you are working but not redlining.
There is a checkpoint cutoff at the 16 mile aid station at 1:00 PM, so this section is not just a fitness test, it is a clock you have to beat. If footing is slow that day, that cutoff matters more than your watch does. Run the rollers honestly and you arrive at the start of the second loop with legs to spare.