Doug, congrats on your successful R-R-R. You peaked my curiosity when you mentioned your 20 hardest hikes. I like researching extreme hikes. Would you care to share your list?
(My version of an extreme hike may be different than someone else's idea of an extreme hike. I'm not trying to be anything, I'm just a chubby retired Navy guy who pushes himself. Your mileage may vary.)
Here's a few - A 70+ mile loop in King's Canyon that was supposed to take 48 hours (it went 60), KC-WP via Colby Pass (48 hours), KC-WP via Forester Pass (48 hours), Mineral King-WP (48 hours), OV-KC-OV day hike, KC-Forester Pass-KC day hike, KC-Simpson Meadow-KC day hike, Half Dome and Clouds Rest via Happy Isles as a day hike. All of the KC (Kings Canyon) hikes started at Roads End and used one of the many trail heads there.
There is a loop hike in Mineral King over Franklin Pass and an unmaintained section of trail, but I don't remember the whole route right now - it was pretty tough.
There's another route in KC that starts at Roads End (like most great hikes do for me) and takes you over Kennedy Pass through a lot of "unmaintained" (not there) trail before you hook up with the trail on the north side of Granite Pass and come back. That one was always tough to get done in 24 hours, but a lot of it was route finding. If there was good trail on the north side of Kennedy I could probably do it in 20 hours.
A few years ago when I had a different hiking partner (who we don't talk about because of the problem on the 70+ Kings Canyon Loop), we would start the hiking season out with Half Dome/Cloud's Rest as our first hike and usually Whitney as our second or third. Then we would cram in as many 24 hour day hikes in KC as we could before wrapping things up with some sort of 48 hour hike. Normally they would involve starting on the West Side and hiking to the Whitney Portal with a Whitney summit side trip. Out of the three big crossings I made it to the summit and to the portal in 48 hours once. Another trip it was 52 hours and one trip I was too tired to go for the summit. The 70+ mile loop I got split from my douchebag partner and later got sick.
I've never successfully day hiked Simpson Meadow from Roads End, but I came close once, doing it in 26 hours.
My all time favorite extreme day hike would be either Forrester Pass from Roads End (and back of course) or my favorite solo day hike of Onion Valley to Kings Canyon (Roads End) and back in 23 hours.
If you want an extreme hike it's easy to put something together in King's Canyon since it's so deep. Start at Road's End, pick a pass and hike to it and back. If you want a tough two day hike start at Road's End and go to Mount Whitney via any route.
And if you really want people to wonder if you're a little nuts, do it with only a can of cake frosting for food.
If you want route info or more details, LMK. I haven't done any big hikes since I split with my old hiking partner in 2009. I think my son (days away from 15) will be able to go 20+ hours next year.
Good luck and have fun. You only need two things for a fun hike - MILES and GAIN..................................DUG