I have a Masters in Writing and teach college level writing here in Ohio. I've also worked as Communications Director for a couple outdoors related non-profit agencies. I've been around outdoor writers a great deal and have picked their brains quite a bit. And every one will give young writers the same advice, "Write, write and then write some more." You only get better by doing it. And once you get something written that you think has a chance of being published, then send it out to as many publications as you can. Then, make sure you have a thick skin because you WILL get rejection notices. Just keep trying. Besides teaching, I freelance and I keep all my rejection letters for inspiration to work harder. Stick to it and you will get published.
As for school, take as many writing classes as you can. They'll help in the pursuit of your education degree as well. You MUST be able to write well to be a teacher. I don't know what subject you want to teach, but a minor in English is never a bad idea and will help your writing immeasurably.
Also, great writers are voracious readers. Read as much outdoors and non-outdoors related stuff as you can. You are already reading Ruark so you are on the right track. Check out the classics like Jack O'Connor, Ruark, Hemingway and others but there are some guys out there now like John Barsness, Tom McIntyre, Mark Kayser, Ron Spomer and more who are really top notch writers.
One last note...keep a journal of your time afield. It will help you when you start to write about your experiences. Oh, I almost forgot...if you don't do any photography already, get a quality camera and learn how to use it. Editors want stories with photos to go with them. Just one way you can help to get your stuff published.
Good luck!