A GPS. It was something I purchased a few endurance rides later, and wished I’d had it from the beginning. Mine was a Forerunner 201 - a wrist GPS, and it was invaluable for showing me the speed I was going, the distance I had yet to travel, how far I’d already traveled, and the time elapsed while on trail (VERY important).
If you can get your hands on one, you’ll see what a wonderful tool it is for an endurance rider.
Also, brings lots of extra blankets for yourself - it is supposed to be VERY cold that weekend at night and it routinely gets below freezing in the valley. Also bring a tarp that you can throw over a rope tied like a clothes line overhead. Your trailer roof is going to build up condensation with the cold, and you don’t want water dripping on your head at night.
Have a plastic baggie for your vet card, and stick the card in a shirt or britches pocket where you can’t lose it.
You can get coffee, juices, snacks, etc at the Ridecamp tent in the morning. Lots of room in the field to walk your horse and stretch its legs before the trail is opened to the LD. The first couple of miles is all uphill, gravel road and mountainside, so TAKE YOUR TIME! Don’t waste your horse’s store of limited energy tackling the mountain at speed, and ignore people that do. Those are the ones that end up getting pulled. Once you hit the crest of the mountain you can trot where you are able, and walk where the rocks demand it.
Since this is your first ever ride, RIDE TO COMPLETE. Don’t race, don’t challenge the trail (you WILL lose). Have your horse shod for this ride - this trail eats boots like candy.
The first loop is about 18 miles long, and will take you about 3 hours. Lots of rock, lots of stunning mountain views. The LD isn’t a race, so don’t get yourself caught up in rushing. Enjoy the views, and come back to Ridecamps with a horse already pulsed down so that you can go right from the In Timer (that will be my domain :)) to the vet check. You don’t want to be among those that will have rushed and now have metabolic horses, lame horses, or sore horses. TAKE . YOUR . TIME.
The second loop is about 12 miles and is entirely in the valley. The trail will cross fields, streams , woods - all on private property. You will have more opportunity to trot here, but make sure your horse is drinking, and allow it time to snatch and eat some grass along the way so that its gut is at optimum and gut sounds are numerous and loud during the vetting.
Remember - don’t race. Ride to complete, and savor your trail time with your horse.
Good luck - and we’ll see you at the ride!