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Routes in Seal Rock

Archaeopteryx T 5.11d 7a 24 VIII 25 E5 6a X
Choose Life S 5.13c 8a+ 30 X- 31 E7 7a
Choose Muscle S 5.13c/d 8b 31 X 31 E8 7a PG13
East Face North Side/Seal Rock T 5.4 4a 12 IV 10 VD 3c
East Face South Side T 5.4 4a 12 IV 10 VD 3c
Gruffalo, The S 5.11a 6c 22 VII+ 22 E3 5c
Hinge, The S 5.13a 7c+ 29 IX+ 29 E6 6c
I Am The Walrus S 5.14a/b 8c 33 X+ 33 E9 7b
Jade Gate S 5.11+ 7a 24 VIII 24 E4 6a
Misbehaven T,TR 5.9+ 5c 17 VI 17 E1 5a X
Primate T 5.13b 8a 29 IX+ 30 E7 6c PG13
Sea Bird T 5.12 7b+ 27 VIII+ 26 E6 6b PG13
Sea of Joy S 5.13a 7c+ 29 IX+ 29 E6 6c A0
Shortcut (East Face) T 5.4 4a 12 IV 10 VD 3c
Skin Flute S 5.12a/b 7b 26 VIII+ 26 E5 6a
Southwest Face T 5.4 4a 12 IV 10 VD 3c
Stoop, The S 5.12b 7b 26 VIII+ 26 E5 6b
Super Tuscan S 5.13b 8a 29 IX+ 30 E7 6c
Supercell S 5.13c/d 8b 31 X 31 E8 7a
Thunder Muscle S 5.14a 8b+ 32 X+ 32 E8 7a
Yellow Door, The S 5.13b 8a 29 IX+ 30 E7 6c
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Type: Sport, 90 ft
FA: Matt Samet, Ted Lanzano, Brett Nelson, and Tony Yao
Page Views: 11,334 total · 176/month
Shared By: Ted Lanzano on Jun 5, 2013
Admins: Leo Paik, John McNamee, Frances Fierst, Monty, Monomaniac

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Access Issue: Temporary Trail and Raptor Closures Details


Thunder Muscle is a new climb between Primate and Choose Life that ascends the spectacular tufa formations to the top of Seal Rock’s south face. The climb was first scoped by Chip Ruckgaber who worked with Colin Lantz and Chris Beh to put in anchors right before the ban (see more info from Chris Beh below). We moved those anchors to the left about 10’ to minimize rope drag. The climbing is very continuous, bouldery, and overall super fun on some of the best rock in the Flatirons.

The start is the same as for Choose Life, clipping the first three bolts of the right-leaning overhang. The route then goes straight up into a series of powerful sequences on steep terrain to a heart shaped feature where you can get a quick shake. After “the heart”, continue through more tricky and increasingly pumpy climbing on pinches, sidepulls and pebbles up to an awkward shelf. A final 12c section guards the chains.

The climb is named after the energy drink “Thunder Muscle” featured on the Increasingly Poor Decisions of Todd Margaret.

As always, thanks so much to OSMP and the Flatirons Climbing Council for this new route and all the other new ones now in the Flatirons.

Please be mindful of the special and delicate setting and stay on the trails!


There are 13 bolts and a two bolt anchor. Long runners helpful at bolts 3 and 4.
Before trying the route, be sure to power up with some "Thunder Muscle":… Jun 5, 2013
The credit for discovering this line belongs to Chip Ruckgaber. He cornered Colin Lantz and me one fine, fall day in '89 spraying about the "tufa" he discovered. We were stoked when we saw the South Face of Seal Rock up close, it having such obvious potential. Chip and Colin climbed up to put the anchor in while I spotted the line from on top of The Pup. We thought we were going to have an awesome crag for winter climbing. The Flatirons ended up being closed to bolting just days later. Good to see you guys taking care of unfinished business! Jun 5, 2013
Curt MacNeill
Boulder, CO
Curt MacNeill   Boulder, CO
What a great route! So polar opposite of its neighbor, Choose Life, it's hard to compare. Very bouldery moves with the crux coming quickly after the knee bar rest at bolt 3. Once you're through the crux, the route stays with you all the way to the top, with a great spot to shake out halfway up on the toilet bowl feature. Lots of body tensiony moves on this one with some bad holds. Other than the "heart"-shaped feature at mid-height, I don't think there is a single jug on this beast. Great route. Super sustained. Power endurance at its finest.... Mar 16, 2014
Elliott Bates
Elliott Bates  
This route is classic. This route is fun. It is hard, but I agree with Tank. With the modern technologies of knee pads, this route is not 5.14. Is it true that Pinklebear did it in sweatpants (obviously sans pads)? In this style (Chuck Norris beast-mode style), I believe it may warrant a 14a rating.

Well done FA, gents. This, along with its neighbor, is an absolute gem. May 19, 2014
Glad you liked the climb, Elliott. I did do it without kneepads, yes, and in ratty cotton sweat pants. I used a left kneescum up at that top crux on the tufa feature. Ted has way better kneebar-tech skills and in addition to that scum had one lower down on the route with his right leg, before "the Heart." I'm guessing other kneebars have been unearthed, using pads, in other spots too. C'est la vie…er, knee. May 21, 2014
Elliott Bates
Elliott Bates  
Well that's just badass, PB! Props to you and Ted for getting this done in two different styles. Fortunately, I don't think TM will "dumb-down" any further with tons of kneebars. I'll slam a kneebar wherever possible, but I only found a few on this one. May 21, 2014
As you may have seen, there is a new trail to access the south side of Seal Rock. From the base of the east face, the new trail goes southeast about 200' and then cuts back up west to the crag. You can't miss the sign. It may take a minute or so longer, but it's far more sustainable, scenic, and pleasant than the former trail. Please don’t use the old social trail that went straight up the hillside. A big thanks to OSMP and the volunteers who made this new trail possible! Nov 29, 2014
Curt MacNeill
Boulder, CO
Curt MacNeill   Boulder, CO
Margo Hayes was up at Seal today and sent Thunder Muscle. I believe that this is the first female FA. Congrats, Margo. Nice to finally see some chicas getting after it on the hard lines up here! Nov 1, 2015
Max Caudle  
Mainly here to spray about doing it, but I also kinda wanna weigh in on the grades, especially with Samet's 13ahole article (…).

Buuuut uhhh, this routes not 14a. Easier than Living in Fear, harder than Choose Life. Everyone is kneebarring their way through the hard bits, so it just isn't that hard anymore. Honestly, the holds might have gotten better since Samet originally did it (I guess that just happened to the Walrus). I mean, take whatever you want for it, but it's hard C or MAYBE soft D. I climbed it as true to the original beta as I could but wore skinny jeans (no pads), not sweatpants. I also jumped past all the hard bits in the middle. If you care, which you shouldn't, here's a video of the middle part:

The important part is that this route is very good, very pretty, and I'm very glad I've been lucky enough to spend time on it. Jun 1, 2018

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