"...Any one know if or where maps that mark such things would be available..."

You can get maps of every national forest from the USFS. Easiest is just to go into one of the offices at each forest and buy one. You can go to their website store (http://www.fs.fed.us/recreation/nationalforeststore/) and order them, or you can usually pick them up in outdoor type stores in cities near a national forest. And of course there are the regular old topo maps, which are not as good (in my opinion) as the USFS maps for this, but they are better than nothing.

Also, if you have a GPS that can display maps (mine is a Magellan Meridian) you can get software that has many, if not all of the roads already in it. I have found in some locations that my GPS shows roads that the paper maps do not...

"...Maybe I need to carry a chainsaw..."

Mucho better, without a doubt. But I rarely carry mine unless I plan on cutting some wood, it is larger, messier, and you have to carry fuel and oil. On the other hand, I ALWAYS have a bow saw and axe in my vehicles. Many of the trees that I have encountered are not all that large, maybe eight to ten inches in diameter, but they were across the road at headlight height. Too big to drag (the ends are always entertwined with other still standing trees), might be a long way to go around (if you can even find another route), but not too big to cut out with a saw and/or axe...

This discussion got me thinking about the state of the roads elswhere in the world...
http://fishki.net/comment.php?id=13808
These pictures are from the main federal road to Yakuts in easter Siberia.
One of the captions says: "The most valuable items around that area are: fuel, food, weapons and towing chains."
Another caption:" Repair crews were not able to reach the road because drivers were severely beating them up."
Another caption: "People were camped out here for more then two weeks, one woman gave birth in a bus."

I've owned 4wd and 2wd vehicles . Although 4wd vehicles come in handy sometimes , they are not the go anywhere do anything vehicles most people think they are . I got stuck in heavy snow in a 4wd once . I 've also plowed through some pretty heavy stuff in a little 4cyl. 2wd pickup . I've driven down some pretty rough roads in 2wd vehicles . Let's say you had to B.O. and you ran into a major traffic jamb . You are in your big 4wd vehicle and think , no problem , I'll just go off raod and go around everyone else . Have you noticed how many vehicles on the road these days are 4wd ? I think you'd just run right into another jamb .

If a disaster is predicted and you don't get out of the way immediately, you're probably going to get stuck, one way or another, 4WD or not.

One think that tends to irritate me here (sorry, guys) is that so many seem to think that if there's a major disaster, THEY will be practically the only ones heading for the hills, mountains, woods, etc.

GET REAL, FOLKS! This isn't the America of the 1880s or even the 1940s. This is America of 2006: we have 300 MILLION people here. We have an average of 80 people per square mile. Does this sound like wide-open Davy Crockett country to you???

If you're headed up the forest service roads, exactly where is it you're heading? Are you aiming for the same patch of timber that a few hundred other people are aiming for? Do you think that everyone else is so dumb that they're just going to sit in their cars on the freeway or turnpike until they turn into mummies?

And how long do you intend to stay there? How much food and water did you manage to pack into the Bronco with your wife and three kids and everything they felt they had to bring along? Do you plan on living off the land with all the other people up there? There isn't going to be a deer or elk or rabbit there within three days.

Planning ahead? Okay.... where do you plan on going from THERE???

Sue, who is in a really pi$$y mood right now

It is truely amazing sometimes the places you can go with front wheel drive. I used to go camping with some friends in the mountains in Pennsylvania (sp?) in Febuary because we all had a long weekend on Presidents day. We would caravan in with 3 vehicles, regardless of the weather. The 4 wheel drive pickup with chains kept getting stuck. I had a front wheel drive Voyager mini van, regular length, with the larger 3L engine. Lots of ground clearance and a lot of weight over the front tires. I pulled through 12" of snow, up hills. Yes I did get stuck, just 1//3 as much as the truck, much to the truck owners anoyance. A group of 6-8 men can pretty much unstick anything though.

As long as you were relatively smart about it, a front wheel drive with decent ground clearance can get through a lot. Having friends with you helps a lot also.