Don’t Get “Moated” in the Mountains in Spring
Be careful around transitional zones between rock and snow
There are a lot of hazards to avoid in the mountains in spring, so be careful when heading out. Transitional boundaries between rock and snow are susceptible to having thin, hazardous snow conditions in spring. In those transitional areas where you move between rock to snow, the rock radiating heat from the day melts away the snow from the underneath and edges, creating what is referred to as a “moat” at the edge of the rock. Finding a safe way to cross the moats can sometimes be the most difficult part of a climb.
When approaching moats, always look for areas that are still the closest to the rock. Your best bet is to find somewhere that the snow is still touching and cross there. Try to plan your timing so that you are crossing when it is early in the morning so you’ll have cooler temperatures and therefore firmer snow.
A belay from your partner can help reduce the chances of a major injury if the moat collapses. The only way to know how thick the snow is at the edge of the moat or how deep it is undercut is to see for yourself. If you are moving from snow to rock, you can lie down on the snow and crawl towards to edge to peek over. If it is a large moat, sometimes crawling down into it and back up the rock on the other side may be the only way to get past. Move through these areas delicately but quickly.