I parked at 4 Corners and hiked up the singletrack hiking trails rather than the fire road, as suggested by AllTrails.  These trails are much more scenic and offer lots of shade.  Once I got to Santiago Peak, I descended down the Power Line Ridge route (mountaineer route) to Old Camp and then hiked up Joplin Trail to Main Divide.  The hike down the ridge was gnarly and, thankfully, someone tied white ropes in between the power line poles for assistance in trail direction and helping on the descent, in my case.  I ran into a couple coming up and as much as the descent being difficult, the ascent was much worse.  I reached Old Camp around noon and ate a quick lunch before ascending Joplin Trail.  Joplin is a beautiful covered trail and offered lots of shade, poison oak, and ferns.  There's a spring along the way if you need any filtered water too!  All in all, a terrific hike.  It took me about 6 hours to travel 9.4 miles with 4,200′ elevation gain.