My brother and I had talked about backpacking a loop of the lone star hiking trail in sam houston national forest over the weekend. I thought it might be worth while to take a .22 magnum and try to call in some coyotes or bag a few rabbits. I have a hunting license along with a public land permit. Is there anything else I need to do this legally?

Sounds like you pretty well have it covered, although it looks like you may need to wear hunter orange when firearm hunting.

http://www.tpwd.state.tx.us/huntwild/hunt/wma/find_a_wma/list/?id=30&activity=hunting

From September 15th to February 1st, you have to stay in a developed campground, no camping along the trail. And be SURE to identify what you're shooting at, a lot of people hunt with dogs out there.

http://www.fs.usda.gov/recarea/texas/recreation/hiking/recarea/?recid=71074&actid=51

Squirrel season is still open too.

Just a heads up, but it is THICK in there.

We hiked all 96 miles of it last spring break so we are familiar with what it looks like. We have the hunter's orange covered, but I was unaware of having to stay in a designated campsites. Thank yall for the info. Also, has anyone squirrel, rabbit, or coyote hunted in the national forest?

That's during the most popular hunting seasons so that someone doesn't accidentally shoot into your camp off in the woods. Safety reasons. Makes it so you have to hike in and out to hunt, too.