You'll be in good company when you climb Greenleaf Peak - Botanist David Douglas was there in September of 1825 without a road or trail. You might think that a hike starting under power lines would not be particularly remote or wild - but once you leave the service road you'll be thinking differently. It's a summit that rarely sees visitors - you might do yourself (and those that might follow) a service by wielding a machete on some of the more overgrown parts of the trail.
You can check www.summitpost.org/greenleaf-peak/153262 for some detailed information and driving directions. We parked a hundred yards up the power line service road and hiked the road from there - a four wheel drive with lots of clearance might get you a little bit further. The rock cairn at the saddle is obvious, but the trail for the first few hundred feet is not at all clear - just keep in mind that the trail stays on the ridge line the entire way up - so if you misplace the trail look for it there. And if you use a GPS, you can download the track that Dan-KK7DS created from here: www.pnwsota.org/content/dans-gps-paths.
There may be a way to drive an additional 4.1 miles on a rough road to get much closer to the trailhead cairn - this would have you parking near 45.717° -121.971° - I've not driven this route but we did see a car there and you would avoid hiking on the very rough powerline road.
Apparently the lookout on the summit was pushed over the edge of the cliff when it came time to remove it but near the summit are the remains of a shed or a small cabin. There's adequate room for most any antenna on the summit and great views of Mounts Hood, Adams, Rainier and St. Helens, although with the trees you don't get to see all of them at once. (The view of Mount Hood can be found by following the ridge north from the summit about 100 meters.)
There was good coverage from AT&T and adequate coverage from T-Mobile for data and voice from the summit. APRS only seemed to work from the summit proper.
