To consider Grosvenor Arch a “diversion” from the Hayduke Trail is probably a bit of a stretch — as it is easily visible from the road/route passing the parking area for the arch. Just another 400 yards or so along a concrete pathway takes one up and underneath the impressive double arch (some may even argue it’s a triple arch!) Depending on the time of day and the sunlight, the arch may appear white or dark orange. If you want to put a bit more effort into the diversion, it is possible to circle the arch to the right and then climb up the slope to get an unique perspective from behind the arch.
The day use area is popular with tourists and has pit toilets and picnic tables, but no running water or trash receptacles. Since it is VERY likely that you will see some aforementioned tourists here, if you share a bit about your hike they may offer some water or to take trash for you. 🙂 However, if you really need water, make sure to do the longer diversion to the solar well to the south for great water before headed toward Round Valley Draw (there’s also a possible water source just south of Round Valley Draw.)
Lastly… if somebody tells you to check out Butler Valley Arch in this same area, well… you just did. That was the original name for the arch before being renamed to honor a president of the National Geographic Society. 👍