There was a couple I remember distinctly. I was trading spots with her husband (guy with white desert hat and black Camelbak). I would see them at the aid stations when I would arrive since we were both roughly running the same time. I got cramps right at the station after I changed socks and she really kindly offered salt tabs. I thanked her for the offer and declined since I had some. Later in the race I saw her running back onto the course wishing me well and telling me her husband was cramping up. Another aid station (closer to the end) a young kid, no more than 12 or 13 was running backwards as well looking or his dad. All along the route I was connecting with fellow runners, 2 that DNF with me at the AR50, another guy who told me to keep my head up, and even one guy I recognized from his finishing picture from UltraRunner Magazine just to mention a few.
I think I have just been spoiled with cool experiences but ultra runners seem to genuinely care about other runners. We all know what it takes to finish and that some days its better to bag it and fight another day then to go blaze of glory status, since that would most likely be very detrimental to your health.