I guess you are are talking about Idaho.
Very Very brushy pretty much describes all of North Idaho.
Steep, deep, brushy and wet.
You don't say where you are from.
If you live in Idaho or close by you will definitely want to do some scouting for an area that looks like the kind of country you want, or are able, to hunt.
The best advice I can give you is be in shape and wear clothes that will keep you warm when wet. Many of the locals wear wool.
Also easy country to get lost in, lots of thick timber. Take a compass, map and GPS with you if you have it.
Not trying to turn you off just want you to know that hunting elk in North Idaho is serious business.
On the bright side there are lots of elk in those areas and get a bear tag as well, you will probably run into some bears up there.
Good luck with your hunt.