2014 Update: The U.S. Forest Service has reopened Eagle Rock and Security Risk climbing areas in Boulder Canyon which have been closed since Feb. 1 to protect golden eagles during their nesting season. Blob Rock and Bitty Buttress areas remain CLOSED.
Each year, Boulder Canyon raptor nesting area closures are in effect starting February 1st through July 31st at Eagle Rock, Security Risk, Blob Rock, and Bitty Buttress. However, the area is monitored and closures are periodically lifted early (due to no active nest, nest site failure, or early fledging). This monitoring program is a partnership with the Forest Service Boulder Ranger District, Boulder Climbing Community, and Audubon Society. Check back periodically during times of closure for updates. More info at www.fs.usda.gov/recmain/arp/recreation.
This information is a public crowdsourcing effort between the Access Fund,
and Mountain Project. You should confirm closures, restrictions, and/or related dates.
I have found descriptions of this route in the following guidebooks: Ament and Erickson's "5.10" (1972); Ament and McCarty's "High over Boulder" (1976 and 1985); Rossiter's "Boulder Climbs North" (1988); and Rossiter's "Boulder Canyon" (1999). In the first of these guides, the name of Tobias's partner is different from the one listed in the subsequent three. Each of these guides contains a different description of the route; BCN has a vague topo that shows the beginning of the route (in a position that is different from at least one of the written descriptions); BCN and BC have good photos of the Bihedral area (without showing the route's location). Rossiter's photos show many possibilities. Because guidebook writers often just paraphrase previously published descriptions, while attempting to disguise outright plagiarism, contradictory and/or vague information is often the result.
Whew — lots of dissection of unimportant trivia — good thing these aren't important trivia.
Yesterday, Leo Paik and I embarked upon a mini-adventure, with the noble intent of finding where Acid Rock really goes. None of it seemed familiar to me, in spite of having climbed what I THOUGHT was Acid Rock in 1975. Turns out what I thought was Acid Rock in 1975 was likely Sun Spot, which happens to be the only route that I haven't SINCE climbed on that whole sector to the left of the Bihedral route.
Back to yesterday: From the base of the Bihedral route, I traversed about 120 feet to the right, placing occasional gear, along the top of a wide slab (which old-guidebook writers called a ramp). I passed what is probably the best, most direct start, up a tongue of gray rock, which would lead up toward a big leftish-facing 90-degree dihedral. Instead, I continued about 20 feet farther right and up, to where I found better placements for a belay anchor, below a bulge and at the top of the wide slab.
Pitch 1: Leo led up and right about 10 feet, placed a cam and moved left, over the bulge (5.7+), He traversed unprotected slab about 20 feet to the bottom of the grainy, 90-degree dihedral, where he placed cam and extended it. He continued to the top of the steepening dihedral, past loose blocks in the funky crack and belayed on a ledge, with lots of loose rock (~90 feet, 5.8+). When I seconded, I removed the first cam and faced a cruxy move with a potentially deadly long swing down into the slab or the bulge next to it. I contemplated climbing back down to the belay, but that wouldn't be easy, and there was also big swing potential. So use double-rope technique, or start at the gray tongue, directly beneath the dihedral.
Pitch 2: I contemplated escaping to the right along this ledge, because above loomed many loose features and no obvious solid pro. After fiddling in a ball nut and tiny cams, I moved up and placed a decent 0.5 C4. Better rock and pro led to a difficult, poorly protected exit past loose blocks, onto a ledge by a seven-foot Douglas fir (perhaps the "pine" referred to in the guidebooks; ~70 feet, 5.8+).
Pitch 3: Leo moved left on the ledge, then angled up and right in a right-facing dihedral-ramp system, then scrambled to the top (~110 feet, 5.7).
Old guidebooks rated this route 5.6. Later guidebook writers perpetuated this rating, probably because they paraphrased old publications without doing any field research.
This route lies above the right side of the Riviera. Any rock knocked off could crash down onto climbers and spectators, kids and dogs, who are oblivious to what lies above. Better avoid it on weekends — and warm weekdays.