Summary - Battle Ax, on the edge of the Beachie Creek Lionshead burn, is hiked from a trailhead above Elk Lake. The trail is often rough and rocky and the last quarter mile, steep. The hike from the trailhead to the summit is about 2.6mi and 1700ft. Trekking poles and shoes good on rock are handy. The summit is open, with the remains of a lookout and views of all the big mountains; you'll need a mast to put up an HF wire. 2M contacts, with a better-than-stock antenna, are possible. I did not turn on APRS and ATT digital service was in and out. The road up to Elk Lake is 2WD possible but it is very potholed and rocky. Be sure to check road reports... FR46 and HW22 are both under construction and delays can be hours long. Combine this one with Mount Beachie (W7O/WV-013).
TL;DR - I hiked Battle Ax and Mount Beachie wiith Jeff WX7OR and his wife Katrina. Because they are smarter than me, they camped at Elk Lake the night before while I left my house in Portland at 5:00AM to meet them in camp. The trailhead for Battle Ax and Beachie is above Elk Lake and there is a small pullout at the start, leave your vehicle here (44.82529, -122.12487). The trail, which is rough and rocky most of the way, gradually climbs up to the saddle between Battle Ax and Beachie, when you reach it (44.81933, -122.14553) turn NE up the nose of the ridge to Battle Ax.
From the saddle you will hike about 1.5 miles and 1400 over a rough and sometimes overgrown trail. The climb is pretty steady the whole way, completely without shade, and brings you to a open summit with the foundation posts of the old lookout. The views are amazing, including the very top of Shasta in the south. There are only young trees and rocks up here, so there's no shade and no place to hang a wire; plan accordingly if you want to do HF or hang out for a while. We were able to work Portland on 2M with a half wave antenna and got half a dozen contacts from there (and closer in) fairly quickly. I didn't work HF since we planned to hike Mount Beachie, too. I also didn't try APRS because, well, I forgot. ATT digitial came and went but I was able to spot.
Travel notes - The drive from SE Portland is about 2.5 hours but there is construction on HW22 and, more importantly, FR46 is only open for brief stretches between 7:30AM and 5:30PM. Check with the Detroit Ranger station to get the schedule and plan accordingly or you could be stuck for a couple of hours.
Summary - Battle Ax is a nice objective, reached by a rough but doable trail, and 2M contacts are possible. If I were camping in the area, I would do this one again just for the hike and views. If it is your first time, plan on doing Mount Beachie, too.