This track is the approach over Easy Ridge to Perfect Pass via Imperfect Impasse. We stayed on Easy Ridge too long and should have dropped down much sooner. Diagonal down to the toe of Whatcom's SW Buttress/Ridge, leaving Easy Ridge around 6.200' and at least 1/2 mile before the ridge blends into Whatcom. Then we went too low dead ended into a vertically walled slot canyon which I assume is the true Impasse. Then, we climbed too high. The way into and across the gully is non-descript. The mellow way into and around this drainage starts around 5,200' and ends at about 5,400 where you can cross the drainage and traverse east to Challenger. See Mountain Project for a pic I posted.