Field mowing....

That's what the local forestry commission and volunteer fire department are for.

Good point.....

Get a farmer or someone with a commercial sprayer to hit the whole thing with Round-up. Then you can see what you've got. Maybe rent a Bobcat and do a little resurfacing. Steep areas can be covered with heavy groundcover plants - find out what the highway dept uses that grows good in your area.

Do plan on covering the hill with ground cover of some sorts. Wife is a bit concerned with critters living in it. We had a big patch of rosemary plants in AZ.....until she seen a snake in it. Local farm supply small sprayers on sale pretty much all summer long....we do have a small tractor....hmmmm

Goats. My sister lives on basically a hill side, has some goats that pretty much contain it. Don't know if that's an option for you or not but does work well for her.

Xs2 ...I had a pair of goats hanging around for awhile and they sure do clean up the weeds and whatever else in the yard.

Did think about goats. Our three dogs would have a field day chasing them. Neighbor suggested just pounding in a few posts, putting up a couple of fence panels and put a goat or two in the fenced in area. When they are done, just move the pen. He had a few goats he was going to bring down when we discussed this....but he decided they needed to be in his freezer instead....