Type: Trad, 2000 ft, 10 pitches
FA: unknown
Page Views: 3,406 total · 16/month
Shared By: George Bell on Jun 8, 2001
Admins: Leo Paik, John McNamee, Frances Fierst, Monty, Monomaniac

You & This Route

11 Opinions

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Access Issue: Temporary Trail and Raptor Closures Details
Access Issue: Seal Cave closure. Details


This is a really fun scrambling route from Bear Canyon all the way to the Fum-Dum col. From here you can continue up to the top of Dinosaur Mountain or Dum. This route is great to do with no rope as there is little exposure during the hard sections, which are more like spelunking. In fact, do not attempt this route if you have claustrophobia! If you take a rope, this route is very long and may take you most of a day. For those who love 3rd-4th class adventure scrambling, this route is definitely 3 stars.

The third stratum on the north side of Bear Canyon is actually split into two pieces, the route follows this division (see photo below). Finding the start of this route is not easy. Leave the trail up Bear Canyon at the first stream crossing, upstream of Stonehenge (this is not the stream crossing on the Mesa Trail). Bushwhack NE, crossing the stream and head uphill (south), at this point you are between the third and fourth strata. A short distance up you will find a break to the east, cross through this and you are now between the two sections of the third stratum. The summit east of you is the top of Stonehenge.

Continue up into a fern filled gully. Finding this gully is they key to the start of the route. At the top of this gully is an ominous black cave with a car-sized chockstone above it, it looks like a dead end. Scramble up a slab and into the cave. The slab is quite smooth and may actually comprise the crux of the route, choose your line carefully.

Enter the cave and continue back into it until you can see the exit, a narrow passage straight up. This is quite claustrophobic, and if you're into rebirthing, this is your place. You will exit into the sunlight at the bottom of a bowl of rocks.

I will describe the rest in less detail so as not to spoil the adventure. The next section is pure hiking, just remember to aim between the two pieces of the third stratum. Several tricky spots here provide interesting 4th class bouldering problems (or harder if you go another way). At one point, a large tree has fallen into the gully of the route. This tree is difficult and unpleasant to pass. Eventually, you will tunnel beneath some giant blocks and emerge right at the Fum-Dum col.

From here a faint trail heads down, eventually becoming the Mallory Cave Trail. Before you do this, it is worthwhile to head west and then up to the summit of Dinosaur Mtn or Dum.


A pair of shoes!
Jake Wyatt
Longmont, CO
Jake Wyatt   Longmont, CO
This route ("trail?") appear to be a great way to avoid the Flatirons hiking crowds. May 9, 2004
There are several large, difficult to avoid, patches of poison ivy on this route/gully. The Black Canyon may have the reputation as the poison-ivy capitol of Colorado, but the Flatirons can be just as bad since it is often mixed in with thick vegetation. Know what the plant looks like, and STAY AWAY. May 20, 2004
There is an exposed move near the top with exposure to the west and a loose block overhead. This may be where the tree is/was, but I haven't been on this route in quite some time. In any event, I opted to retreat a bit, escape to the west, and ascend the loose and unpleasant Bowling Alley gully en route to Dum, a spectacular place indeed. After scratching up my clothes in the hole lower down, I had resolved to at least accomplish that. I will reserve comment on the poison ivy issue. Jan 22, 2006
Mike McMahon
Little Cottonwood Canyon, UT
Mike McMahon   Little Cottonwood Canyon, UT
This is one of my favorites: caves, routefinding, noxious weeds, a few climbing moves! There must be at least half a dozen tunnels though out this route. Jun 17, 2007
Tried this route last weekend and it looks like the first cave has collapsed. The rest of the route still makes for a fun scramble! Nov 20, 2008
Rob Nevitt
Louisville, CO
Rob Nevitt   Louisville, CO
Sunday August 30, 2007.

My brother Mike and I took a very circuitous route to find the entrance of the first cave at the following GPS point:

N 39 58.22.7
W 105 17.23.7

The cave is definitely NOT collapsed! Great scramble. Sep 3, 2009
P. W.
P. W.  
My friend and I did this yesterday and were nearly turned back; the first cave-like feature you see when you pass between the portions of the Third Stratum has collapsed. We decided, thankfully, to keep going and look for the rest of the route, only to find that the actual cave in the route description is the SECOND cave-like feature up the hill, and it is not caved in.

After the cave, the rest of the route is mixed scrambling and hiking. The route description in the Flatirons Guidebook says this is a good training route for alpine scrambles and I agree. The combination of a long route with multiple scramble sections, loose rock and routefinding was great practice.

A+, would climb again! Jun 29, 2011
Tony B
Around Boulder, CO
Tony B   Around Boulder, CO
Mostly a hike- lots of dirt, a little rock. Great as a hike, so-so as a climb. Finnish via the summit of the back ridge of Dino Mt for a slightly longer day. Jul 15, 2011
Eric Klammer
Boulder, CO
Eric Klammer   Boulder, CO
If you're looking for a continuous rock climb, this is not for you. If you're looking for a very fun scramble/adventure hike off the beaten path, then try this! Have done this route multiple times, and it is always a blast. When dry, I'd recommend descending via the climber's trail on the front side of Dino Mountain. A little hard to find, but once you do, it's only a few minutes of steep trail and an easy downclimb until you are back on the main easier trail system. Much better than the Bowling Alley.... Jan 30, 2013
Brian C.
Longmont, CO
Brian C.   Longmont, CO
Went to do this again today, and the cave section is now marked as being under a permanent bat closure. So, I guess for now this section of route is now a no-go and needs to be bypassed. Feb 6, 2015