FATMAP difficulty grade
Narrow Gauge is a narrow crack that allows for a straightline.
You must first hike up to Jacque Peak's Shoulder and then proceed down the ridge and past the main Headwall's entrance.
There will most likely be a cornice to negotiate at the top and expect decently steep turns all the way (though the pitch isn't as extreme as one might expect).
The run narrows eventually and there's only one path down which requires a mandatory straightline.
The straightline section isn't too steep and is wide enough, although it feels extremely scary to funnel between two massive sets of cliffs .
After this section you'll merge onto the Western part of Cornice Bowl and you can take the runout all the way back.