Inspired by a post on Facebook, I decided to do a rundown of what I carry with me on a SOTA activation. This tends to be a pretty personal list, different people carry wildly different things, but this works for me.
In the warmer months, I run lighter.
From the right side:
-Osprey Talon 22 Pack
-Leki Corklike Trekking Poles
-Essentials kit in a ziplock, containing matches, a mirror, flint/steel, a small flashlight, a mylar blanket, a whistle, aquatab water purifiers and a compass
-American Morse Porta Paddle-II
-2m Arrow II Yagi in a homebrew pouch, the 70cm elements are left at home
-Sunscreen and bug spray (these are a bit large, usually it's smaller ones)
-Corona Folding Pruning Saw (for light trail maintenance, cutting blow downs and such on the trail)
-Ziplock with TP and a shovel for digging scat holes
-Ziplock with small notebook and pen for logging
-Pouch for HF station, containing my feedline, a 9V battery (not pictured), the key, a homebrew 20/30/40m linked dipole made from speaker wire, and an MTR-3B 3 band CW transceiver
-Random rope for hanging antennas
-ACR ResQLink PLB (better to have it and not need it then need it and not have it)
-Light rain coat
That pretty much covers it. I also will use a camelbak for water, a 100Oz one that fits in the pack. Sometimes I'll run a different HT, sometimes I'll have a hand mic with me. The arrow will sometimes stay home if I'm doing an HF activation. I've found the poles are a must, and I rely heavily on them to protect my knees. If my arms aren't sore when I'm done hiking, I'm using them wrong. I'm looking to replace the porta paddle with an integral touch keyer, it's just a project that I haven't completed yet.
The saw may be a lot of excess weight, but it's nice to be able to clear large branches that are down on the trail. I wouldn't recommend using it unless the branch is blocking the path, but if the wood isn't cleared then hikers will start to go around. This causes the trails to widen, or other trails to form, and causes unnecessary damage.
The MTR is a nice little radio. It'll run for an age on a standard 9VDC battery. It covers the 3 bands my antenna covers. I had a Yaesu FT-817ND, but after one hike schlepping it up a hill I had enough of the weight. It's a metric ton. I'll also carry a Shakespear Wonderpole if I'm expecting a rocky summit without trees to support the antenna.
In the winter, the base kit stays much the same, I just add a lot more stuff.
As you can see, a lot more stuff.
The pack switches to a the Osprey Atmos 65. This is mostly because of the piles of clothing required on summit. Usually I'll hike in a light coat, warm pants, water proof over pants, and maybe a water proof shell jacket. On the summit, when I'm not moving for a while I need more clothing. Usually a fleece jacket or vest, heavy gloves, hat, maybe a face mask. This is all bulky and I need the space in the bag, so the larger bag it is.
Continuing clockwise, we have a couple traction options. In New England, we can get a wild variety of conditions on the trail, so I generally won't carry all of these - pick what makes sense. The snowshoes are Tubbs Mountaineer, and also on top of the yagi bag are Kahtoola Microspikes. The 'spikes are always with me, and will get me through most of the hikes I'll do. I haven't carried the snowshoes on an activation yet, but if I know there's a good snow base on the trail they'll be coming. I just haven't had the opportunity recently. The goggles are Smith Knowledge OTG, useful for when it's blowing hard out. The orange bag is my Black Diamond Contact crampons. These are carried rarely up here, but we can get icing even on the lower summits that are pretty gnarly even with microspikes. The red pouches are insulated pouches for nalgene style bottles, in freezing temperatures they'll ensure I still have liquid water. I'll fill them with slightly warm water and place them cap down in the pouch (ice will freeze towards the bottom first, then). I also replace the baskets on my poles with snow baskets, usually I don't run with any baskets at all to prevent snags and leaf gathering. Not pictured are all of the assorted clothes that I wear - fleece lined track pants, heavy Darn Tough Mountaineer socks, assorted jackets and vests, and whatever else I feel conditions warrant. I also must point out the amazing Turtle Fur Fog Free face mask, which is the only thing I've found that keeps my face warm in the wind while not fogging up my glasses.
I also carry a small first aid kit, which I just noticed isn't pictured.
Hopefully this'll help someone decide what they should carry!