This "mountaineer's route" is probably the easiest way to climb from the alcove between Arrowhead Spire and the East Buttress to the crest of the Northeast Ridge. Begin up and left from the big ledge that runs beneath the Rorschach face on the East Buttress. The main feature is a 180 foot V-slot that runs the entire height between what could be called Ledge One and Ledge Two. A second "pitch" goes straight up, then left up an easy ramp to the crest of the Northeast Ridge. This is a good scrambler's route to the summit of Arrowhead, though most scramblers will want to rope up for the V-Slot and most of the second pitch.
Take the usual approach from Black Lake and gain the alcove between Arrowhead Spire and the East Buttress as descriped in previous guide books. There are two good ways to reach this point.
From the summit of Arrowhead, the easiest way down is the South Ramp aka Summit Ramp.
The entire thing is a no-pro scramble except for the V-Slot, which is a real pitch. Bring gear up to 4 inches and forget the thin stuff.