REI Community
The Bihedral (Upper Tier)

Routes Sorted
L to R R to L Alpha
A Fly in the Ointment T,S 
Acid Crack T 
Acid Rock T 
Bihedral T 
Bihedral Arete T,S 
Blood Diamond S 
Case of the Fags T 
Crack Variation T 
Dan's Line S 
Daydreaming T 
Diamonds and Rust S 
Dihedral Variation T,S 
Edge of Reality S 
Fat Tuesday T,S 
Flags of Our Fathers T,S 
Flesh Eating Flies S 
Group Therapy S 
Hesitantly Decisive T 
Heterohedral T 
High Hard One S 
Hold The Line S 
It's Time For Change T,S 
Just Putin Around T 
Left-Handed Tool T,S 
Night Moves T,S 
Oh Boy T,S 
Pariah S 
Puff Daddy S 
Rhodian Shores S 
Rhodian, Naturally T,TR 
Sands of Iwo Jima S 
Sun Spot T,S 
Thumb Tack T 
Tool King T,S 
Trick or Treat T,S 
Where's Ray? S 

The Bihedral (Upper Tier) Rock Climbing 

Photos:  Recent | Best | Popular
Elevation: 7,020'
Location: 40.0035, -105.3964 View Map  Incorrect?
Page Views: 47,222
Administrators: Leo Paik, John McNamee, Frances Fierst, Monty, Monomaniac, Kristine Hoffman (sitewide)
Submitted By: Kreighton Bieger on Jan 1, 2001


77° | 50°

69° | 43°

52° | 40°

49° | 36°

49° | 35°
You & This Area
Best climbs for YOU in this area
Your opinion of this PAGE:    [0 people like this page.]
BETA PHOTO: Approach to The Riviera and The Bihedral.

  • Seasonal Closure MORE INFO >>>
  • Seasonal Raptor Closures MORE INFO >>>

  • Description 

    The Upper Tier of the Bihedral is typical Boulder Canyon granite climbing. Generally less than vertical on bullet-hard grey granite. Good friction with a high concentration of slopers, both large and small, and positive incut edges. The crag itself is identified by a huge, left-facing dihedral and sits on the north side of the canyon. The dihedral is split by a prow about 1/2 way up, the Bihedral.

    There are quite a few good routes here, but the most well known is the 2-pitch Bihedral route, which Rossiter so obtusely refers to as "something of a classic".

    This area gets good sun and is sometimes sheltered from the wind, which can make it a great place to climb on windless, warmer, winter days.

    With a number of new, moderate, mostly bolted routes, this area is a popular place to bring groups and less-experienced climbers. Beware, there are still plenty of loose rocks above.


    A. Left-Handed Tool, 8, 1p, 70', bolts & gear.
    B. Tool King, 8, 1p, 60', bolts & gear.
    C. A Fly in the Ointment, 10-, 1p, 60', bolts & gear.
    D. Edge of Reality, 12- R, 1p, 60', bolts.
    E. Case of the Fags, 11+, 1p, 70', gear.
    F. Acid Crack, 10, 1p, 60', gear.
    G1. It's Time For Change, 8, 1p, 95', bolts & gear.
    G2. Night Moves, 7, 1p, 60', bolts & gear.
    above G2. Daydreaming, 10, 1p, 40', gear.
    above G2. Oh Boy, 10+, 1p, 80', gear.
    G3. Diamonds and Rust, 8+, 1p, 80', bolts.
    H1. Fat Tuesday, 10+, 1p, 90', gear & bolts.
    H2. Heterohedral, 9- PG-13, 2p, 240', gear.
    H3. Hesitantly Decisive, 9- PG-13, 1p, 100', gear.
    I. Blood Diamond, 11+, 1p, 80', gear & bolts.
    J. High Hard One, 9, 1p, 80', bolts.
    K. Group Therapy, 8-, 1p, 100', bolts.
    L. Dan's Line, 8-, 1p, 100', bolts.
    above L. Puff Daddy, 10-, 1p, 65', bolts.
    M. Trick or Treat, 8-, 1p, 100', bolts & gear.
    N. Sun Spot, 7, 1p, 100', gear & bolts.
    O. Hold The Line, 9, 1p, 100', bolts & optional gear.
    P. Rhodian, Naturally, 9- R, 1p, 100', gear.
    Q. Rhodian Shores, 10, 1p, 80', bolts.
    R. Bihedral, 8+, 2p, 240', gear.
    above R. Crack Variation, 9 R, 2p, gear.
    S. AHR, 11c/d, 1p, 70', bolts.
    T. Dihedral Variation, 9+, 1p, 100', bolts & gear.
    U. Bihedral Arete, 10-, 2p, 180', bolts & gear.
    V. Where's Ray?, 8+, 1p, 60', bolts.
    W. Flags Of Our Fathers, 10-, 3p, 200', bolts & gear.
    above W. Sands of Iwo Jima, 11+, 50', bolts.
    above W. Thumb Tack, 11+, a final pitch, 1p, gear.
    above W. Pariah, 12, 1p, 80', 8 bolts.
    X. Just Putin Around, 9 PG-13, 4p, gear.
    Y. Acid Rock, 6-8+ PG-13, 3p, gear.

    To the right:

    Z. Flesh Eating Flies, 11-, 1p, 60', bolts.

    Getting There 

    Drive 7 miles up the canyon (zero at the bridge a la Rossiter), park just before the Riviera at a pullout on the left (same pullout as for Happy Hour Crag), or continue 0.2 miles to shady parking on the left side, just past a guard rail, identified by a west-facing "No Camping" sign nailed to a tree. The huge left-facing dihedral of the Bihedral is obvious above you.

    Cross the road, walk down a bit and find a path that zig-zags up the hill, generally heading right (east). When the trail nears the rock on the right, spot a big pine tree next to the rock. Walk right behind the tree and go left around a rock rib. Climb up the rock, with one short 3rd-class section, to a nice ledge at the bottom of the big dihedral. See photo for the easiest approach.

    To return, reverse the above approach, or else walk 50' left (west) on a path just below the Bihedral route, to a 2-bolt rappel anchor. Rap 95' down a gully to the top of the approach trail.

    Climbing Season

    Weather station 4.4 miles from here

    37 Total Climbing Routes

    ['4 Stars',0],['3 Stars',6],['2 Stars',23],['1 Star',8],['Bomb',0]

    Classic Climbing Routes in The Bihedral (Upper Tier)

    Mountain Project's determination of the classic, most popular, highest rated climbing routes for The Bihedral (Upper Tier):
    Sun Spot   5.7 5a 15 V+ 13 MVS 4b     Trad, Sport, 1 pitch, 100'   
    Trick or Treat   5.8 5b 16 VI- 15 HVS 4c     Trad, Sport, 1 pitch, 100'   
    It's Time For Change   5.8 5b 16 VI- 15 HVS 4c     Trad, Sport, 1 pitch, 90'   
    Dan's Line   5.8 5b 16 VI- 15 HVS 4c     Sport, 1 pitch, 100'   
    Bihedral   5.8+ 5b 16 VI- 15 HVS 4c PG13     Trad, 2 pitches   
    Heterohedral   5.9 5c 17 VI 17 HVS 5a PG13     Trad, 2 pitches, 200'   
    Hold The Line   5.9 5c 17 VI 17 HVS 5a     Sport, 1 pitch, 100'   
    Dihedral Variation   5.9+ 5c 17 VI 17 E1 5a     Trad, Sport, 1 pitch, 100'   
    Bihedral Arete   5.10a 6a 18 VI+ 18 E1 5a     Trad, Sport, 2 pitches, 180'   
    Flags of Our Fathers   5.10a 6a 18 VI+ 18 E1 5a     Trad, Sport, 3 pitches, 200'   
    Puff Daddy   5.10a 6a 18 VI+ 18 E1 5a     Sport, 1 pitch, 65'   
    Daydreaming   5.10- 6a 18 VI+ 18 E1 5a     Trad, 1 pitch, 40'   
    Rhodian Shores   5.10b 6a+ 19 VII- 19 E2 5b     Sport, 1 pitch, 100'   
    Acid Crack   5.10b 6a+ 19 VII- 19 E2 5b     Trad, 1 pitch, 80'   
    Oh Boy   5.10c/d 6b+ 21 VII+ 21 E3 5b     Trad, Sport, 1 pitch, 80'   
    Blood Diamond   5.11c 6c+ 24 VIII- 24 E4 6a     Sport, 1 pitch, 80'   
    AHR   5.11c/d 7a 24 VIII 25 E4 6a     Sport, 1 pitch, 70'   
    Sands of Iwo Jima   5.11d 7a 24 VIII 25 E5 6a     Sport, 1 pitch, 50'   
    Thumb Tack   5.11d 7a 24 VIII 25 E5 6a     Trad, 1 pitch, 60'   
    Browse More Rock Climbing Classics in The Bihedral (Upper Tier)

    Featured Route For The Bihedral (Upper Tier)
    Rock Climbing Photo: Tony Bubb arrives at the steep section of 'Thumb T...

    Thumb Tack 5.11d 7a 24 VIII 25 E5 6a  Colorado : Boulder Canyon : ... : The Bihedral (Upper Tier)
    This route is one of two routes up the striking headwall that caps the Bihedral.This climb can be seen easily from the road on the top 1/4 of the Bihedral. It starts in a overhanging handcrack for a few meters, gains a small square pod/cave, then exits the feature on the right hand side in sustained tight finger-locks and sidepulls, going up to a tree at the summit.P1: Approach via the climb Rhodian Shores, Crack Variation, or Bihedral Arete. After the belay common to all of those, continue, te...[more]   Browse More Classics in Colorado

    Photos of The Bihedral (Upper Tier) Slideshow Add Photo
    Rock Climbing Photo: Approach to routes on the upper tier of the Bihedr...
    BETA PHOTO: Approach to routes on the upper tier of the Bihedr...
    Rock Climbing Photo: Don't forget that you can rap down from the upper ...
    Don't forget that you can rap down from the upper ...
    Rock Climbing Photo: Beautiful winter's day on the Bihedral.
    Beautiful winter's day on the Bihedral.
    Rock Climbing Photo: It's all about perception.
    It's all about perception.

    Comments on The Bihedral (Upper Tier) Add Comment
    Show which comments
    Comments displayed oldest to newestSkip Ahead to the Most Recent Dated Jul 29, 2017
    By Ron Olsen
    From: Boulder, CO
    Mar 15, 2007
    On 3/14/07, Mike Amato and I installed a new 2-bolt rappel anchor about 50' left of the Bihedral Route/Rhodian Shores/Hold The Line area. This provides a descent back to hiking terrain without having to do the 3rd-class downclimb.

    From the ledge below the start of these climbs, walk climber's left (west) about 50' to the end of the ledge and a 2-bolt rappel anchor. Rap 95' down a gully to the top of the approach trail. A 60m rope works fine. See ??.
    By jcntrl
    From: Smoulder, CO
    May 13, 2009
    Just FYI, this is not a great approach for our canine companions. I've twice seen climbers attempting to bring their dogs here, once successful with a few scary dog-moves on the traverse, and once bailed entirely. Best just to leave them at home for the day if you're going to climb here.
    By cdg
    May 21, 2009
    I will say it again but Mountain Project will probably remove my remarks like they did before. There is no reason whatsoever to have a rap station where Ron put it. You can climb 3rd class up but you need a rap station to get down. Just save your bolts to squeeze in yet another route on a crag that is now over run with routes. Loose rock is right!!
    By George Bell
    From: Boulder, CO
    May 21, 2009
    I have to admit it does seem crazy to have rappel alternative to a 3rd class downclimb. I noticed these bolts when we were up there but we just walked down. I suppose the bolts could be useful in a downpour, or something. Since they are there, I'd not suggest removing them.
    By Ron Olsen
    From: Boulder, CO
    May 21, 2009
    Don't use the rappel if you don't want to -- but it's useful in bad weather, if you have a heavy pack, or if it's getting dark. I did a lot of route development at the crag in the winter, and came down that rappel by headlamp several times, with a 40-lb. pack. I wouldn't have wanted to do the 3rd-class downclimb in those conditions.

    So all you hardmen, do the downclimb blindfolded if it makes you feel superior to us gumbies who do the rappel -- I really don't care. The rap anchor is staying.

    And cdg -- if the Bihedral is such a crappy place to climb, go someplace else; no one is forcing you to endure the terrible conditions there. You won't be missed by all those who are having a good time at the crag.

    You might also try contributing something positive, both to this site and the local climbing community, instead of just bitching about something you don't like.
    By cdg
    May 23, 2009
    Ron, I am not trying to be an ass . All I was saying is that I don't think it is nessessary. This area was once a great place with some great routes, but now it can be down right dangerous with all the new climbs. 45 people on that one ledge is just not right. That is what I experienced one day, and you were there, so you have seen it too. Just food for thought when you guys are putting in new routes.
    By Ron Olsen
    From: Boulder, CO
    May 25, 2009
    cdg -- the most people I've seen at the Bihedral is 31 (not 45), on a sunny and warm Sunday Feb. 22, 2009. The Bihedral is one of the nicest places in Boulder Canyon for moderate climbing on warm winter days; hence the crowds.

    We've done our best to make the area safe and fun. All of my new routes have lowering hooks instead of ring anchors, which reduces the possibility of screwups while cleaning toprope anchors, and lets climbers get in more pitches in less time. The climbs are well protected and the rock is clean. We've removed a lot of loose rock, but some still remains -- on It's Time For Change and perhaps other routes. Be careful and wear a helmet if others are climbing above you.

    Sorry if crowds bother you, but the area is popular for a reason. Climb during the week or on a hot day -- you'll have the crag to yourself.
    By JohnJ80302
    From: Boulder, Colorado
    Jun 5, 2009
    Used the rappel bolts tonight when the rain moved in after our 3rd climb. Very quick and handy. Thank you Ron and Mike for putting those in, as it saved us a slippery descent.
    By ravisurdhar Surdhar
    From: Phoenix, CO
    Jul 3, 2009
    Had some fun on the Dan's Line slab today...thanks for giving us directions down at the road, Ron!
    We belayed a little lower down from where you're supposed to I think, down by the dirt and pine trees. A little more comfortable than higher up, and it's in the shade. Two caveats: it's a long way up to the first bolt (but the climbing is easy), and my 70m was getting fairly close to the end when I came back down after setting it up for top roping.
    By Rick Casey
    From: Lafayette, Colorado
    Jul 5, 2009
    There is a new bolted route just left of Group Therapy, which I led today, which I believe has been put in since fall 2008. Felt like 5.10+ at a couple of moves in the crux near top, though most of rest of route was easier. If I'm not mistakened, I do not see that this route is documented here. Is this a new route, or am I mistakened? Thanks for the info....
    By Rick Casey
    From: Lafayette, Colorado
    Jul 5, 2009
    Just read all the past comments on the highly popular area developed primarily by Ron Olsen, and noticed the negative comments about the rap bolts placed by Ron left of the main belaying area for the Upper Tier. This may be a little bit belated but:

    To the negative commenters about the rap anchors: hey, get a life, will ya? Go ahead and downclimb the 4th class approach if you want; why bother about commenting about it here, spreading confusion and disinformation?

    This is a SPORT climbing area, is relatively high up on the canyon wall, and is quite susceptible to sudden thunderstorm activity. EVERY time I've been up to this area (about 6 times in the past 6 months) EVERY body uses the rap anchors, and PREFERS to use them (even in good weather). Downclimbing is more difficult than climbing up, especially with a pack; and the 4th class climb up is certainly exposed during the initial section. Installing these rap anchors, at a very sensible location, only makes sense given the exposed descent route.

    I was rained off this area on a recent afternoon in a pounding rainstorm (on Fri, June 26), and I and my partners MUCH, MUCH appreciated that these rap anchors were there! Thank you Ron for putting them in!
    By Ron Olsen
    From: Boulder, CO
    Jul 5, 2009
    Rick Casey wrote:
    There is a new bolted route just left of Group Therapy, which I led today, which I believe has been put in since fall 2008. Felt like 5.10+ at a couple of moves in the crux near top, though most of rest of route was easier. If I'm not mistakened, I do not see that this route is documented here. Is this a new route, or am I mistakened? Thanks for the info...

    The climb immediately to the left of Group Therapy is High Hard One, which is documented on this site. The crux is at the top, and I rated it 5.9+, although it would be harder on wet rock. There are also two more routes to the left of High Hard One (and right of Diamonds and Rust) which are not documented here. They are 5.11 and 5.12 routes put up by Bob D'Antonio, which will appear in his soon-to-be-released Boulder Canyon guidebook.
    By cdg
    Jul 25, 2009
    Does it really matter that this is "now" a sport climbing area. Was not allways that way.That was my point!! Again, I was not trying to dig in deep about climbing politics,just didn't think it was something the area needed.4th class? Please.Down climbing in the rain? Welcome to the mountains city folks.
    By Paul Donald Andrews
    From: Nederland, Co.
    Jun 11, 2010
    I'm a Yosemite veteran and this is the best crag I've climbed on, so far, in Boulder Canyon. I'm not a 5.12 leader, but I can appreciate that places like Animal World, Coney Island and Easter Rock hold a better concentration of high quality climbs. And I'm really looking forward to Cosmosis, Avalon, Upper Dream Canyon, etc. But for the pure joy of fun in the sun rock climbing, this area has it. Excellent rock quality, safe routes, various styles and spectacular position well above the road are a few of the reasons I like this place so much. I even like the 3rd class approach. It adds a sense of remoteness and adventure to an area so easily accessed. The ledge is a comfortable, clean and fairly spacious spot as opposed to a lot of base areas that are dirty, slanted and trashed. Helmets are probably a good idea, especially when there are a lot of other climbers, but that is true of most areas in the canyon.
    My first climb here was Rhodian Shores. I didn't have a guidebook and it looked like a nice, direct line. There were parties on some of the other lines to the left, so we jumped on it. I was a little surprised to find out later it was a 10b. At the belay, I got to watch a guy lead the first pitch of the Bihedral Arete. Wow, it really looked spectacular from that vantage point. I was obsessed with doing it. It took 4 attempts to complete both pitches, because of rain, and partners. I finally ended up leading both pitches, after leading the first one 3 times. It's a climb I would go back to any time. It looks so improbable from the road. It's hard to believe it goes at 10a. Can't wait to do the second pitch of Rhodian (10a) and the routes to the right of the Arete.
    By Tony B
    From: Around Boulder, CO
    Jun 16, 2010
    What are the mixed/trad routes to the right of It's Time For a Change?
    There seems to me finger crack to the right which merges to the anchor, then a bigger crack going right of the main corner at a horizontal, then up a shallow dihedral and crack up to set of higher anchors.
    Anyone know?
    By Eben Daggett
    From: Boulder, CO
    Nov 21, 2010
    Hello all, I lost a draw here yesterday (Saturday, November 20th). If you find it, please contact me and I will describe it. Thanks!
    By justin hausmann
    From: Fort collins
    Nov 22, 2012
    Used rap anchors after freak snow storm last year. Nice to have in a sport area.
    By Adam Kroz
    From: Boulder, CO
    Apr 1, 2013
    I left a navy blue Icebreaker thermal up here yesterday, in case anyone picked it up. Thanks!
    By Fiona Dunne
    From: Boulder, CO
    Jul 22, 2014
    This evening I picked up someone's roll of tape with what looks like a 12V-to-USB charger in the center. PM me if you want it back.
    By -- Chris --
    Nov 10, 2014
    This is probably obvious to everyone else, but just in case... if you park at the lot 0.2 miles past the Riviera parking, you want to walk along the road in the direction towards Boulder to find the path that "zig-zags up the hill." At present, the trail is marked by a small cairn on the left of the road.

    Also, for what it's worth, I appreciated the rap anchors from the ledge to the trail. :)
    By Mark Roth
    From: Boulder
    Jun 5, 2016
    I have the biners you left on the rap bolts from the ledge, if you want them back. Those are rap hangers you can thread the rope directly through BTW.
    By JD Tulloch
    Jul 29, 2017
    I left two draws on the anchor to Dan's Line yesterday after a crazy rainstorm blew in. If anyone happens to snag them before myself, please let me know! Thanks, guys.

    Mountain Project

    The Definitive Climbing Resource

    MTB Project

    Next Generation MTB Trail Maps

    Powder Project

    Backcountry Ski Maps & Secret Stashes
    FREE Stickers · Gyms · RSS · School of Rock · Contact · About