I have flown a Cessna 150's out of short strips in Western Montana and Idaho for a long time. It is a great performer when flown light,(by yourself) early in the morning when it's cooler, and with half tanks. If you deviate from these rules, everything changes very quickly. It does well on the standard pitch propeller. It can be operated in the Montana/ Idaho backcountry safely, if always following the above rules.
I had a Cessna 150G when younger. I flew it everywhere I wanted to go, with no Stol kit, stock propeller. I now do the same type flying in a friends Cessna 150D. It does have a Stol kit and the manual flaps. It is awesome! I enjoy the extra safety margin as I'm older now with a Stol kit:) A poor man's bushplane! It makes me feel rich, no pun intended. You have to learn to manage the power you have available and you can do so safely. If it's all that's available on your budget, it's fine.
The best thing you could do for a Cessna 150 is take it to Willie Stene in Polson, Montana and have him put a Sportsman Stol kit on it. This goes for the 172's, 182's etc. The Cessna 150 is a great fun responsive airplane that will teach you a lot, until you can upgrade to something better. 1200' grass strips are no problem, but you always, always, always be aware of density altitude, and fly light. Fly light, fly tight.
The home strip in Pinesdale:
http://www.youtube.com/watch?v=DLOEDRtP6jMThe Selway in a Cessna 150:
http://www.youtube.com/watch?v=sF36wlKKJGoMakes me want to go fly.
Richard