Need help entertaining a Plott Hound mix

Trying again, I posted this in the wrong place before...

Hello,

I have a 10 month old female Plott Hound/Pit Bull mix named Maple. She is sweet as can be and I love her to death but she is giving me a run for my money. Maple is my first hound. I've had plenty of retrievers and pointers but this is a whole different ball game. Maple lives with Pride (13 yr old English Pointer), Barney (8 yr old Shepherd/Chow mix) and Morgan (2 yr old Xoloitzcuintle) plus two foster puppies, Patch (lab/dalmatian mix) and Bo (pit bull). She gets tons of exercise on our daily walks, playing with the puppies, running on the treadmill and obedience training but none of this is fulfilling her need to get out and run through the woods forever. I cannot keep her from digging out of the yard or going over the fence and in some cases going through the fence (that pit bull head is a battering ram). Now that she has gotten over her motion sickness I try to take her out everywhere with me to socialize and give her some exposure to the world but it's not enough. She is also going through a very severe and extended fear phase for the last few months. People tell me it's the Pit Bull side of her causing this and she'll outgrow it. I sure hope so, she's training to be my service dog and can't do it if she thinks all sconces are the devil.

What do I need to do to satisfy Maple's instincts so she will be content to stay at home? I don't hunt and I don't know anybody who does otherwise I'd send Maple off with them for the weekend and tell them to bring her back on Monday in one piece! We adopted Maple as an 8 week old puppy. We knew she was a Pit Bull mix but didn't know the mix was Plott Hound until she started growing into it. Now that I know I want to do everything I can to make her happy. We live in Gastonia, NC. If there is anybody around here who can help please contact me! In the meantime all suggestions are welcome.

Thank you!