Depends on what you are willing to spend. want it fixed for a good long time?? gona take a saturday worth of work and a bit of $ on your part. my sugestion will depend on your location.
do you have a good truck? (minimum of 3/4 ton, any smaller is unsafe for pulling a big heavy trailer) if so procedd like this
Go to your friendly nieghborhood rental guy, and rent a mini excavator, preferably a bobcat 330 (mines a 331) somthin series, just the right size, not too big or too small.
Controls are pretty user friendly, and it has a stabilizer/grading blade on the front of it too (which will come in handy later on during the project)
hop in your rental, scrape back about 12-18 inches (all depends on location) of the dirt. where you dispose of that dirt is up to you. this also depends on how wide you want to go. if we're talking 8 feet wide by 60 feet, you'll need about 20 tons of #3's for your base (you could go 304's, but i preffer just big ones for base)
lay them in about 8-10 inches deep ( thats what i use for a driveway that will see a privatly owned semi tractor, you can pry go lighter if its just for a jeep, say 4-6", )
then cover those up with straight 57's, about 10-15 tons will do it (again, thats open to the needs of your job, but that would be my best guess. And, you can never have too much spare gravel!)
gauren-damn-teed to last for quite some time.