Rating of ski touring routes

There are different standards for rating of ski touring routes in different areas, we try to adopt, and are working on getting at least one grading available across all regions. But for now, we have two rating models. KAST and Alpine Grade.

Alpine Grade for rating of ski touring routes

In the alpine grade system the grade of a route indicates the highest technical difficulty you’ll encounter underway. It also reflects how demanding it is, providing an overall difficulty rating. However, even routes graded as ‘Easy’ can be very challenging. For example, a snow-covered knife-edge ridge with steep drops can feel extremely serious despite being technically easy. Remember, grades can vary significantly in terms of technical difficulty and seriousness. Use them as a general guide.

F : Easy	≤30°	Soft, hilly smooth ground
PD : Less difficult	≥30°	Predominantly open slopes with short steep steps, obstacles with alternatives, hairpins bends necessary
AD : Quite difficult	≥35°	Short steep steps without alternatives, obstacles in moderately steep terrain, safe hairpins bends necessary
D : Difficult	≥40°	Steep slopes without alternatives, many obstacles, perfected and safe techniques required
TD : Very Difficult	≥45°	Continuously steep terrain, often interspersed with rock steps, many obstacles in short succession
ED : Extremely Difficult	≥50°	Extremely steep slopes or couloirs, no opportunities for relaxation on the descent
EX : Beyond Extremely Difficult	≥55°	Extreme cliffs and couloirs

KAST, a Norwegian translation of ATES

In Scandinavia we use KAST, a translation of ATES (Avalanche Terrain Exposure Scale), for rating of ski touring routes. This system does not necessarily reflect the difficulty of the slope, but the level of avalanche exposure the route has.

KAST 0: Non-avalanche	No known exposure to avalanches. Very low-angle or densely forested slopes located well away from avalanche paths, or designated trails/routes with no exposure to avalanches.
KAST 1: Simple	Exposure to low-angle or primarily forested terrain. Some forest openings may involve the runout zones of infrequent avalanches and terrain traps may exist. Many options to reduce or eliminate exposure.
KAST 2: Challenging	Exposure to well-defined avalanche paths, starting zones, terrain traps or overhead hazard. With careful route finding, some options will exist to reduce or eliminate exposure.
KAST 3 : Complex	Exposure to multiple overlapping avalanche paths or large expanses of steep, open terrain. Frequent exposure to overhead hazard. Many avalanche starting zones and terrain traps with minimal options to reduce exposure.
KAST 4 : Extreme	Exposure to very steep faces with cliffs, spines, couloirs, crevasses or sustained overhead hazard. No options to reduce exposure; even small avalanches can be fatal.