Hey, This is Courtney Ley (not Lea, but very close
) Depends on the time of year. I climbed Wait Until Dark Gully in the Great Gulf in November and I approached it from the Great Gulf trailhead.. There was not a ton of snow, so the approach on the trail was easier, but negotiating in the ravine itself can be a battle. Here's the story: http://neice.com/2013/11/the-great-gulf/
Once the snow starts flying in mid-winter, it's tough to access, but totally worth it. Any approach would be long. I would recommend, not going up Airline or Valley Way (not very close
) but heading up Nelson Crag or climbing a ravine in Huntington crossing over the Auto Road and then dropping down. In Spring, this approach would be mint.
Also Gabe's approach is good two cents.