Summary - I first hiked Lookout Mountain via the usual route, High Praire Trail, Tim N7KOM as part of a two day outing that included SOTA summits 6001 and Badger Butte. This time, I took the long way up, starting from the Gumjuwac trailhead on HW 35 before picking up the Divide Trail to the summit, a ten mile round trip with 3000 feet of gain. While the last couple of miles are a little rustic, most of the hike is on a good trail through open, older forest. There is adequate parking in a "chain up" area within a hundred yards of the trailhead. The summit of Lookout, which is open and flat, has the foundation of a lookout and outbuilding, great views of all your favorite peaks, and plenty of places to set up an HF antenna. Two meter contacts are likely to be sparse given the big rock (Mount Hood) between you and Portland/Vancouver.
Long Version - Lookout Mountain, on the west side of Mount Hood, is usually reached via the High Prairie Trail. Tim N7KOM and I activated Lookout by that route in 2021, along with driving the length of Bennett Pass Road and the truly terrible Terrible Traverse, to activate 6001 and Badger Butte. With 3000 feet of gain and a ten mile round trip, the Gumjuwac and Divide Trail approach is a bigger commitment than High Prairie and a nice hike through older forest and alpine meadows with good views along the way.
The drive from Portland to the trail is about ninety minutes, at least early in the morning. The trailhead (45.33946, -121.57033) is clearly marked and you can park in the "chain up" area (in the winter this space may be off limits) across the road. The trail climbs 2.5 miles and 1600 feet from the highway to the Gumjuwac Saddle through open forest. The Bennett Pass Road runs through the saddle and the Divide Trail is on the east side of the road, running parallel to it for about three-quarters of a mile. Past a spur trail to High Prairie it will turn east and climb toward the summit of Lookout.
The Divide Trail is easy to follow but less traveled than the Gumjuwac and is, in late summer, overgrown in stretches. You will pass through a burn scar, open forest, alpine forest, and meadows. You will also work your way over, around, or under eight or ten sizeable snags. This is definitely a sturdy shoes, long pants hike. With the exposed and open stretches, sun protection is a good idea, too.
Lookout's summit is flat and open with great views in all directions. Bring a mast if you want to put up an HF wire and don't count of two meters to get your four QSOs: Mount Hood is directly between you and the Portland Vancouver Metro area. It can be windy on top but there are a couple of tree-sheltered areas that make good operating positions.
All told, Lookout is a good summit for a leisurely activation and the hike up from HW 35 is definitely worth the effort.