Getting firewood down a mountain

I'm in south central BC and we have 20 acres that goes up the side of a mountain. We have a lot of fir (Douglas, Grand, Balsam) and cedar with a sprinkling of birch. I'm wondering if someone has any ideas of harvesting trees on the side of a mountain. It was logged 40 years ago and there are a few overgrown skidder trails still visible but mostly game trails. I'm in my mid 60's but I walk on the mountain everyday, but I struggle with ideas of how to get firewood I cut down the mountain except piece by piece. I don't have a quad or any gas driven machine. Any creative ideas most welcome !!!

Zipline?

Logs used to go down slides, but I think these were generally water-assisted...

The terrain and details of the goals are going to determine all the details of the process. How steep... how far to where you want the wood... are you clearing small areas to use all of the wood in a convenient area or trying to selectively pick thru all 20 acres?

Do you live on site, or hauling wood away?

Joseph - somebody mentioned a zip line and I know in logging they use something called a high line, but I don't know how they work and I would have to set it up which seems like it might be a challenge.
Dillon - We live on the site (straw bale off grid) - and I would prefer to selectively log rather than clear cut an area of all decent trees. The terrain is well treed and quite steep but not too steep to hike around in except by the very top of the property. Like I said - I am walking around on the property every morning so not so steep to keep me off.

Can't you cut and stack in situ?  Once the wood is dried it will have lost over 80% of its weight making it easier to move.

Growing-up-in-the-Yukon story-time again.  At a place called Jack Wade on the Taylor "Highway" (162 miles of misbegotten summer-only gravel road between Tok, on the Alaska Highway, and Eagle, on the Yukon River) there was a burn, some time in the 1960s.  And at a place in the road so steep that the road took a switchback, the burn was high above the road.  When we moved to Eagle in 1973, it was an area designated for public firewood cutting by the Bureau of Land Management (BLM, aka "Bunch of Lazy Men").  

So my father took his wife and four kids (ages 6, 9, 12, and 14, roughly) out there and climbed way the hell-and-gone up above the road.  Started cutting these huge standing dead "blue wood" spruce trees with the bark already fallen off and cutting them into firewood lengths with his ancient Homelite C5 chainsaw.  So we had wood in all sizes from one inch stobs to 30" rounds.  Then he basically told us all to start carrying it down the mountain.  Mom was limbing and bucking with a smaller chainsaw so the kids were unsupervised.  

How long do you think it took my sisters to figure out that the larger rounds would roll and bounce all the way to the road if they could get them going fast enough?

How many shits do you think they gave whether any of those rounds hit "the brat" on the way down?  

They had never heard the phrase "that's not a bug, that's a feature" but the spirit of it was alive and well on the hillside above Jack Wade switchback that day.  "Catch Daniel with a bouncing wheel of blue spruce" became the best fun they'd had since we hit that country most of a year before.

In another thread somebody indirectly characterized some of the routine experiences I had growing up as stuff they'd consider child abuse.  I rejected the characterization in that context, but I accept it in connection with almost every memory that has to do with collecting and preparing firewood.  Which, considering that we burned through as much as 20 cords a winter in our first cheechako cabin, is a lot of them.  

But I tell this story now because at the heart of it is a practical moral: in the right situation, cutting the wood into rounds and rolling it down the mountain can get a hell of a lot of wood off the hill in one heck of a hurry.  

I think I would be inclined to slide it down the slope lengthwise.
A mechanical or electric winch pulling down slope, a drag line to slow it down, complete with some kind of resistance, maybe a counter weight?
A tarp for the wood to ride on/in and something to keep the front of the load from digging into the dirt as it is pulled?
The cutting and drying in place is a good idea.
If you can trade wood for work make a deal with someone to log your land?

I think I would try to trade some of my logs to a guy with a tractor that could skid logs down to a place near where I wanted them to be cut into firewood.  A guy with a tractor can move a heck of a lot of firewood in the form of logs in a day.

Cutting and rolling is fast but hard work. It is how we did it here for years... though sometimes they keep going past where you want them and continue down the mountain.
 I would fall, them limb them up nice and clean ,  use cable/ chains and a come along to slide them down . Heck with a drag line to slow it down, just stand back and let it slide as far as it likes.

Thanks all for great ideas - bucking them up in place to let them dry is good - definitely be lighter and the idea of a cable and come along is something very do able for me alone. Rolling them downhill has been tried but they keep running into other trees or going off sideways etc but I may try all of these ideas.