nah dude, its illigal to camp outside of a designated camp ground. i mean, send off into the woods a half mile and no one will notice if your sneaky about it, but you can just throw down a tent anywhere. welcome to america, home of the pussy robots
then as far as ski-bumming on mt hood/ some free stuff you can do in govy...go to the lodge across from the thunderhead and the gate the the showers/ pool is usually open...so you got your free pool right there also.
or, if thats closed, the security passcode for errything at the thunderhead is the thunderheads adress. So you can go in there and play pool/ping pong also.
don't take chances and just make sure they're 18+ and you're fine
otherwise, you can camp at the airstrip for free.(http://maps.google.com/maps?q=mt+hood+national+forest&um=1&ie=UTF-8&sa=N&hl=en&tab=wl) Trillium Lake about a mile away has a campground but it is expensive as shit ($16/night?). Same with the campground up near Timberline (not to mention it doesn't open till really late and gets bloody chilly at night).
In the Mt. Hood National Forest, and pretty much all national forests for that matter, you can camp nearly anywhere for free, as long as the stay doesn't exceed like 2 weeks. In some places it isn't OK, such as right next to hwy 26 or in other places. Usually if it is a backroad and there is ample room for your ride and tent and shit or off a backroad (e.g. airstrip), you're fine.
You can even camp above or around Timberline. Of course that isn't as convenient, but it can be done.
i lived in a tent at hood this summer, its a must for any true ski bum.
the third night something big came across my tent, after that i slept in the truck. but i made it three days in the woods without even going down to govy.
after hermit-ing for a week or so i joined the "civilization" known as government camp.
Camping at hood is the best. Met a bunch of really cool people at the air strip, some new schoolers, a shit load of people from idaho and utah, and an old santa claus looking dude that goes by darrel who gave us free beer and dry wood almost everyday. Just bring a tarp and alot of beer.
the biggest thing i hate.. is how people trash the fuck out of it... shit and garbage every were.. like poop every where.. shit in a bag and throw it away!
I lived in a tent for like to weeks in Mammoth last summer and it was epic...You can legally camp in any BLM (Bureau of Land Management) land at any time, anywhere in the country. Mammoth has the added bonus of having natural hot springs for soaking , as well as some great fly-fishing. Bumming it is the shit, period.