A running joke in Boulder, Colorado, is that the Flatirons are an artificial backdrop that the City painted on the Boulder Mountains, to attract tourists. When snow ices the formations like a wedding cake, or a hot July sunrise makes them glow blood-red, you can almost (almost) believe the urban legend. These strange Fountain sandstone slabs, spires, boulders, and aprons are too surreal to be true.

For me and many other “prefer-to-climb-alone-in-the-trees” lifers, the Flatirons are about as good as climbing gets. The sometimes steep, punishing hikes from the plateau of the Enchanted Mesa up to the walls have always kept crowds down, save on the First, Second, and Third Flatirons, with their regal 5.0-to-5.4 slab classics. And the ambiance, once you’re back in the gullies, is killer: a distant hum of city noise, wind through ponderosa pines, ferns and shrublets underfoot, endless new-route and bouldering potential. These rocks are all things to all climbers: moderate multi-pitch paradise, hard-sport mecca, dodgy trad and headpoint wonderland, and a boulderer’s bounty, with more blocks still probably unnamed and unclimbed than yet documented.

Much-needed and much-welcomed is Jason Haas’ new Climbing Boulder’s Flatirons ($32, sharpendbooks.com), a 220-page, comprehensive, full color, photo-topo guidebook that pulls together all the roped climbs. A bona fide Flatirons disciple, Haas spent three years on the book, climbing almost every route on its pages — no small feat when you consider that more than a few of these climbs are obscure, dangerous mystery routes up poison-ivy-choked gullies and on formations most Boulder climbers barely know by name (Schmoe’s Nose, Nixon’s Nose, or Hillbilly Rock, anyone?). Haas’ perfectionism and love for the area jump off each page — it’s clear from the thorough descriptions that he knows these routes. One nice touch is, on the easier multi-pitch routes, the author doesn’t walk you through pitch-by-pitch, but instead leaves the adventure and route-finding open, as is often organically the case with the wander-anywhere (but find pro nowhere!) east slabs.

Bonuses: essays by key figures in Flatirons history (Tom Hornbeim, Roger Briggs, Hank Caylor, etc.) and stacks of sharp action shots from top local photographers. As one of America’s most important but often-overlooked crucibles, the Flatirons deserved this exhaustive effort.