By the mid- to late-'90s, sport-style mixed climbing was in full swing in the Rockies. Bolted lines meant good protection for the steep rock sections, but the ice was still your regular old hard-to-protect WI5/6 shakefest. Big falls were still available despite the bolts as Raphael Slawinski demonstrated while attempting the second ascent of Teddy Bear's Picnic (V M8 WI6, 200m). He managed to on-sight the overhanging limestone but snapped the hanging curtain near the end of the pitch sending him for a 30-meter whipper that he miraculously walked away from.

For these modern mixed routes, climbers began using the M grade system to rate the difficulty. M grades were introduced by Jeff Lowe (the originator of WI grades as well) in the mid-'90s to combine rock and ice grades into one simple number that defines the crux of a mixed route. The M system is open-ended, presently ranging from M1 to M10 with + and - added. Unlike rock climbing, one cannot split hairs over mixed grades. Mixed routes are much more dynamic. A hold may break, a dagger might snap off, thin ice could melt, moss might get scraped off, all of which make subsequent ascents harder. The following chart will give a general idea of how strenuous a certain M grade may feel.

M4 — 5.8
M5 — 5.9
M6 — 5.10
M7 — 5.11
M8 — 5.11+/5.12
M9 — 5.12+/5.13-
M10 — 5.13