FATMAP difficulty grade
Castle Ravine holds a high spot on many bucket lists.
However, a number of logistical challenges make it a hard one to check off.
It's northern aspect is often scoured by the prevailing NW winds in the Whites, keeping conditions thin and crusty.
It also only sees almost no sun in winter and just a few hours in spring, not to mention access requires a slog monster approach, no matter which direction you come from.
With that being said, if you catch it in the right conditions, Castle Ravine offers some of the longest and most sustained steep couloirs in the range.
A number of approaches are possible, the shortest is to go from Castle Ravine Trail, however, this is hard to follow in the winter and crosses the river multiple times.
A more reliable but taxing approach is to climb The Cog, then take Gulfside Path to Cornice Trail.
Castle can also be combined with King Ravine for a lengthy linkup tour.
Middle Sister is the most narrow gully of the 3 Sisters.
It's upper and lower sections offer excellent steep skiing, but an ice bulge crux in the middle makes it and unreliable option for a continuous descent.
Begin with narrow turns that progressively get steeper.
The line opens up to skiers left under a rock wall, be careful here as there is a cliff beneath you.
Move skiers left to skirt the large ice bulge.
In some years this is all snow, in others this is a rock crux or a smaller ice bulge, making a rappel or air time necessary for exit.
Below the crux, more steep skiing awaits before you reach the runout.
Join the same runout as North Sister and ski even more excellent turns all the way to the brook.
Unlike other ravines, which tend to flatten out at the bottom, Castle continues to drop dramatically until it all converges in the center.
From here, cross the brook to Castle Ravine Trail or throw crampons on and reverse your approach back to where you started.
Even with a big snowpack, Middle sister still involves skiing above a large cliff, and like all Castle Ravine lines, a fall would likely send you all the way to the bottom with serious consequences.
Treat this line with a high degree of respect and be prepared to self rescue in the event of an incident.