Technical Grades WI1-WI 7
The technical grade accounts for the most difficult pitch of the climb. It takes into account the steepness of the climbing and also ice conditions such as thickness, and texture of the ice (e.g. chandelier or cauliflower ice).
WI 1 Walking up ice where crampons are necessary but not used for climbs. A frozen lake or streambed.
WI 2 A pitch of 55- to 60-degree Ice at a reasonably consistent angle. Good protection and belays.
WI 3 Sustained 70 degree ice, with short sections up to 85 degrees and usually thick and solid. This may include short, steep sections but will have reasonable resting places and offer good protection and belays.
WI 4 Sustained pitch of 75 to 80 degree ice or a pitch of ice that is not so sustained but which may have a couple of significant vertical sections with resting places in between. Generally good quality Ice offering secure protection and belays.
WI 5 A strenuous pitch of good but steep (85-90 degrees) ice. Long vertical sections broken up with only occasional resting places. Ice is good but may be very thin, protection may be reliable but will take some effort to create, may sometimes be run out.
WI 6 A very steep strenuous pitch that may be vertical the entire way with very few resting places. Ice may be of poor quality, thin and protection may be difficult to secure. A high level of skill is required.
WI 7 Vertical to overhanging terrain. Ice may be thin, poorly bonded to the surface beneath it, and offers only poor protection for the leader. Climbing skills demand creativity. Don’t even think of falling on this grade.
Mixed Grades M1 - M7
The mixed grade is a general idea of what to expect technically and how hard you will have to pull on the route. It does not take into account the nature of a route; i.e., well protected or runout, objective hazard, length of your climbing day.
Gear requirements on the mixed routes can include a full compliment of protection; ice screws, spectres, pitons, stoppers, and cams. Some mixed routes will be totally bolted.
The general thought on relating the M grades to the Yosemite Decimal System (YDS) is that the “feel” of a certain grade is present. Example; M5 “feels” like a 5.9 route rather than actually being 5.9. Remember you are wearing mountain boots, crampons, and torque your ice tool picks in cracks. The following comparison will give you an idea of how strenuous and tenuous the route should feel: