Summary - Most folks drive to the Larch parking lot and walk up to the observation platform. This is the long way up. You will start from Multnomah Falls on I84 and climb 4200 feet over seven miles. Trail 441 begins on a steep, paved path that is often thick with tourists, at least for the first mile or so. After that, you'll likely have the trail, which often rough, traverses a couple of burn scars, and climbs steadily, to yourself. On the summit, you will share the small, popular observation platform with other visitors, so this is best planned as a handheld activation. Depending on the time of year and your start time, you will need a "timed entry" permit to park in the Multnomah Falls lot. Yup, if you like "earning" your SOTA points, this is the hike for you.
TL;DR - This is my fourth visit to Larch. I've done the parking lot version along with a hike and a snowshoe from the snow gate at the 10 mile marker. This time I decided to get my two points the long way, hiking the Larch Mountain trail 441: 4200 feet of up over seven miles from the Multnomah Falls parking lot (and back). If you plan on starting after 900AM, visit recreation.gov for a timed entry parking permit. I started at 700AM and, theoretically, didn't need one but purchased a 900AM permit and left it on my dashboard, just in case. Multnomah Falls is a very popular tourist stop; consider an early start time.
The hike starts at the base of the falls, climbs steeply up a paved series of switchbacks with lots of places to stop and watch the water drop. After roughly a mile and 800 feet of climbing the trail splits and most everyone turns right toward the falls. You will go left, drop down and begin following Multnomah Creek up the canyon. There are two or three more waterfalls along the creek, each attracting a number of visitors; after the last falls, about 1.5 miles in, you will probably have the trail to yourself.
At this point, though the climb is steady, the steepest part of the hike is behind you. The trail is often rough, and in the late summer, overgrown in sections. Sturdy shoes, long pants, and long sleeves are a good idea. You will hike through old and new forest, cross several burn scars, navigate a couple of scree fields and hike a section of the trail that is under water in the spring. The climb onto the ridge of Larch Mountain starts roughly 2.5 miles and 1200 feet from the top. At the end, follow the trail to the stepped path to the observation platform and, on a clear day, enjoy the terrific view. Plan for a quick activation as this is a popular destination and the platform is small. 2M contacts are usually pretty easy, especially if you spot yourself. If you want to put up an HF antenna, look to the right, below the observation platform, for a small area that is out of the way. It is not ideal but workable. BTW, if you find a Criket pocket knife back there, let me know. I left it behind on my first visit.
The whole thing works out to seven miles or two thousand one hundred feet per point. While not the most efficient sort of SOTA outing, it makes for a good day in the Gorge.