It’s the “10,000 feet” part that is extra-impressive. There is a huge difference between 100km and 100km with 10,000 feet of climbing. Wow.
Well the hills keep it from getting dull 
Here’s the altitude profile of the course: Miwok 100K Official Website | Altitude Profile
The second-to-last spike was the killer for me; part of it is a set of rudimentary stairs set into a steep oceanside bluff and when the stairs run out the slope continues, just with worse footing. Immediately after you crest the top there’s two miles of downhill to the final aid station. My quads were pretty beat up by this time (~55.5 miles) and I couldn’t run the downhill so I just walked as fast as I could to let my legs recover a bit. Had some hot soup, food and Pepsi at the aid station, pep talk from my g/f and took a couple of ibuprofen (something I never do during a run) to help with pain and swelling for that final push. Speed hiked the last rise and was then able to run the last couple of miles.
Oddly enough the earlier climbs weren’t that bad - legs are fresher and I had company so we could talk to pass the time.
Some of the longer races look far worse - WS100 has over 20,000 feet of climb in 100 miles, Hardrock 100 is over 30,000 feet in 100 miles (they’re proud of the fact that it’s more than climbing Mt. Everest) and I’ve spoken to a couple of guys who ran an Italian race that goes 207 miles with 80,000 feet of either climbing or total change (either way that’s staggering).
I did a solo 50K with 9,200’ last year in the White Mountains of NH, and that took me 12 hours. I’m trying to contemplate doubling that.
For those interested, here’s a video from 2011 Miwock 100km (not mine – just saw it on a forum – and the guys in the video are flying). Miwok 100 2011 - YouTube
Gorgeous looking course. Those incline at Miwok look pretty brutal! It looks like it’s up, or down other than the probably-not-as-flat-as-it-looks jaggies between 20-30 and 40-50. That’s gotta be brutal on your quads going down. 18% grade early on? Gah! Plus some running on sand? That’s not an easy looking course. (not that any 100K is easy)
Regarding the 100 milers, I’ve seen some photos from Hardrock that had me drooling to run that. The 30K feet climbing aside, I think the avg elevation of 11K feet would do me in. I live on the coast at about, maybe 11 feet above sea level! Oddly I do mostly mountain ultras… slowly (50K’s with 7000 feet gain, 50 miler with 9000 feet gain) but never peaking above 4000 feet. If I’m ever on the west coast I’ll have to give Miwok a look!
How often do you do hill training? Do you get to run bits of the course for training?
That’s a cool video. I remember Ian Sharma (Elvis) passing some of us on the way back as we were still on the way out. Yes, some of the hilly sections are pretty steep and really pound on your legs - for example the turnaround at mile 33.7 comes at the bottom of Randall Trail which drops about 1000 feet in 1.5 miles. You can see some of the leaders running back up it in the video. The men and women at the front are pretty amazing.
Even some of the gently rolling stretches were challenging - for example those shots of runners going through tall grass on a hillside don’t do justice to the very narrow singletrack which has gopher holes and is on enough of an angle that the uphill ankle starts to hurt after a while. The weeds cover the trail pretty well so it’s hard to see exactly what you’re stepping in. Some of us had to avoid a rattlesnake.
As far as training goes, I think that every step of the way is on public land so you could go out and run the whole thing tomorrow if you wanted to (although I’d be careful on the paved stretch at the beginning due to traffic). The entire Bay Area is blessed with beautiful state, local and national parks with mile after mile of amazing trails to run, anything from nice wide gentle fire trails to some brutal climbs/descents. As I mentioned I hadn’t been able to do much dedicated training for this event but some of my favorite runs in the hills of the East Bay are just as steep, long and have even worse footing than what I ran Saturday so I think I had a decent base going. Even if I run out my front door and stay on city streets I’m guaranteed plenty of hills.