Type: Sport, 80 ft
FA: Eric Fedor?
Page Views: 11,488 total · 54/month
Shared By: Pinklebear on Sep 19, 2001
Admins: Leo Paik, John McNamee, Frances Fierst, Monty, Monomaniac

You & This Route

127 Opinions

Your To-Do List:

Add To-Do · View List

Your Star Rating:

     Clear Rating

Your Difficulty Rating:

-none- Change

Your Ticks:

Add New Tick
Access Issue: Temporary Trail and Raptor Closures Details


A Flatirons mega-enduro overhanging classic! Long (80 feet), pumpy and just plain fun, this is a must-do for the grade.

Undertow is the third route from the right on the imposing, overhanging west face of The Slab. It is well-shielded from the Fern Canyon trail by a thick, piney forest and climbs a spectacularly colorful wall on (mostly) positive horns, crimps and jugs. Expect some bizz-ness up by the lip.

This route is very-chalked up and quite easy to find.


Six bolts to double-bolt anchors; you can stick-clip the first bolt. There is a also a single belay/directional bolt on the ledge. Some people use cams between the fifth and six bolts on the flaring crack out right.

Per Will McNeill: WARNING: the 3rd bolt pulled out 12/16/17, leaving the route in an unsafe state. As is, there is a lot of decking potential through the thin moves before bolt 4.


Scramble around to the west side of the Slab from the Fern Canyon Trail and continue uphill (south) past the towering middle section of the wall. Undertow starts from the right side of the large ledge splitting the face and can be reached via a series of 3rd class ramps.


Richard M. Wright
Lakewood, CO
Richard M. Wright   Lakewood, CO
I was hoping to get this route in myself. This is a great line on mega jugs, and very steep for this area. Who can forget the classic shot of Robyn Erebsfield hanging by one hand and a foot blasting through this route like a toy. Since it starts at the base of the Slab it stays in the shade essentially all of the time. What makes Undertow interesting, beside the climbing, is that it went in during Boulder's controversial years when the West faces of the Flatirons were on the verge of exploding with hard new lines. Undertow was an important harbinger of this potential as much as Dale Goddard's Five Year Plan was defining the possibilities. What a loss. Sep 24, 2001
Joe Collins
Joe Collins  
Front Range sport climbs don't get much better. The actual count is 6 bolts to a 2 bolt anchor, with cruxes at the 3rd and 4th bolts. There is a #2 Camalot placement between the 5th and 6th bolts in what looks like an old bong scar, but it looks like it wouldn't hold a fall. There is also a good #1 Camalot placement to protect the moves to the anchor.

There are a couple, what look like, pin scars on this route and lots of hookable features. Does anyone know the history of this route? Was it originally an aid line? Apr 16, 2004
Ken Cangi
Eldorado Springs, CO
Ken Cangi   Eldorado Springs, CO
Getting to this route is a bit of a hike but worth it. Undertow has it all - beautiful rock, great position, pumpy angle, interesting movement, and solid clipping stances. This and Chains of Love are two of my favorite Flatirons routes. Jul 20, 2005
I agree with much of the above, this was a very memorable and fun route for me! Don't be afraid to schlep those draws up here, it's beautiful in many ways (including the climbing!) Mar 21, 2007
Some knucklehead felt the need to spraypaint graffiti right next to the start of this route. WTF? Sep 24, 2007
Morrison, CO
Monomaniac   Morrison, CO  
Maybe it was the convicted graffiti vandal Daniel Woods. Sep 25, 2007
Brett Merlin
Boulder, CO
Brett Merlin   Boulder, CO
The #2 Camalot placement is totally jingus, bring a #0.75 and/or #0.5 Camalot instead. Pretty good placement right below the bad #2 placement. Oh, and also a #1 Camalot for the top if you want it. Jul 25, 2010
Phil Lauffen
Innsbruck, AT
Phil Lauffen   Innsbruck, AT  
No real need for extra gear. The moves above the fifth bolt are a little heady, but quite easy. Currently there are fixed draws up this entire route....

Also, here is a nice video Kurt made of me on the route.

youtube.com/watch?v=uyTQ478… Jun 14, 2011
Kurt Ross
Kurt Ross  
Dan Yager
Fort Collins
Dan Yager   Fort Collins
Fun little route! Not as good as The Shaft over at Dinosaur but definitely worth the hike! Sep 28, 2011
Ben Sachs  
I placed a 0.5 Camalot/grey Alien-sized piece (grey Alien is better). Not truly needed, but it's nice and right where you'd want it (after the crux). Didn't feel the need for anything else. Apr 24, 2012
TheBirdman Friedman
Eldorado Springs, Colorado
TheBirdman Friedman   Eldorado Springs, Colorado
Does anyone do a full-on cut loose dyno for the jugs at the lip? This is the way I did it, and it is pretty awesome. Due to the angle of the wall, literally every part of your body, except your right hand which grabs the jug is flying away from the wall. I have seen people doing it statically by locking off on some bad holds and getting high feet. I think it's more fun to go from the crescent moon hold that you use to clip and then just huck for it. Jan 5, 2013
Mississippi James
Riverside by way of the dir…
Mississippi James   Riverside by way of the dir…
DYNO is the way to go! Big style points. Jul 21, 2014
Will McNeill
Denver, CO
Will McNeill   Denver, CO
WARNING: the 3rd bolt pulled out today, leaving the route in an unsafe state. As is, there is a lot of decking potential through the thin moves before bolt 4. Dec 15, 2017
Will McNeill
Denver, CO
Will McNeill   Denver, CO
The 3rd bolt is back!

I would be extra careful with this one though, and make sure it's screwed in before trusting it. It is positioned such that it is likely to be unscrewed a little each time the rope is weighted on any higher bolts (e.g. working the crux or lowering off the anchors), so once it starts to spin a little, it won't be long before it unscrews all the way. Mar 27, 2018
^^^ Regarding the 3rd bolt - maybe a glue-in should be placed here? Mar 28, 2018