I have a question when trying to teach my gsd the marker wait(stay) which he knows in a environment of high distraction. This is where I am coming from. Koda is a gsd that I adopted two months ago and has bonded with me extremely. He looks to me for guidance on everything and listens to all the commands that are given. However I am scared to test him to be free of the leash in our yard for I live on 15 acres in the mountains of VA. We have deer, squirels, and every other wildlife including black bears which he tracked one a couple weeks ago lol. I'd love to be able to let him off the leash at home however he has a huge drive when it comes to this wild life. We take long walks in the woods and always stir up deer and when we do he is ready to jump on it after them. Like daddy please please please can we go get them, are the a toy. This is my concern. That if I was to attempt the no leash that if a scent of something or the sight of something was around he go right after it. Naturally if I am over a friends who has three gsd's i let him off the leash and he follows my every step like at home in the house. How or where do I start to eventually have him in the immediate yard without fear.

Does he have a solid sit or down from far away? I'd say starting with these and having him doing these on a long line with high distaction (along with a solid come command) would be a good start. If he can come at 20 feet off an animal scent, your going in the right direction

Long lines are you're friend!

Do you think it will ever be possible to have him off the leash with such a drive for wildlife?

Yep, if you spend the time working on a long line, increasing distractrion levels over time.

My dogs will stay in a down with a chipmonk running past them only 7-8 feet away. Crazy chipmonk...playing chicken like that. :-)

I down my dogs & chase gease off the field or have them chase them & then I call them off.

My male is high drvie, my female is VERY high drive. It can be done...just doesn't happen overnight. Training takes time & patience.

Deer are so tempting with their flagging tails and bouncy run, like a giant bunny.

 Quote: joseph eubank

Do you think it will ever be possible to have him off the leash with such a drive for wildlife?

Yes!
Look at the "drive for wildlife" for what it is. A very high level of distraction but nothing more then that. That's nothing more then a training issue.
Get your recall solid without distraction then add sloooly.
A solid response to "NO"! can also benefit.
I hunted with terriers for years but they could still be called off of a rabbit, deer, etc.

 Quote: Joseph Eubank

Do you think it will ever be possible to have him off the leash with such a drive for wildlife?

Just another vote for YES!!!! It takes time. (and a long line)