Another of those impromptu trips to take advantage of good fall weather.  Road #3040 no longer goes all the way to the trailhead.  At a crossing of Fossil Creek about 1.5 miles from the Mt. Baker Hwy (#542) the road ends at a washout.  High clearance vehicles might make it over the washout, but for the Subaru it was the end of the line.  Hike one mile up the road from the washout to the beginning of Trail #671. 
The trail gains 3900' in something like 4.5 miles so you'll get a good workout.  The lower part is all in trees, but at about 5000', you break out into an open meadow below the craggy summit ridge.  It must be awesome in the early summer when I'm sure it's covered in wild flowers. Looks like it may also be a great place for summer huckleberry grazing as well. 
Leaving the meadow, the trail traverses to a S ridge and then in a couple long switchbacks arrives at the short rocky scramble path to the old lookout site.  Pass a decaying outhouse and debris from the lookout building on the way.  Great views all around today, from the Border Peaks and Mt. Larrabee to Shuksan and Baker and all the way out to Puget Sound. 
As an alternative, find a boot path leading up the S ridge from where the trail hits the ridge.  It goes the same place, but without the long switchbacks below the summit ridge.  There is also a spur trail you'll cross that goes to Kidney Lakes on the N side of the ridge.   If you decide to take the "cable" route up or down from the lookout site, be careful of the loose rock.  Anything kicked loose, goes a long way and crosses the trail below.
Very nice trip and considering that I was the only guy in the group, even more enjoyable.  The organizer of this and many other trips has also posted a trip report on WTA, which you can find here.