Hard to say. I don't jog, but my friends who do find that while it great for the heart, jogging on the streets doesn't prepare your leg muscles for the incline on something like Skyline.
Stairmaster...I would die if I only had access to that or a treadmill. Those things are for dedicated and disciplined folks IMO. I get bored in about 5 minutes.
Find something local and smaller, and do laps. Luckily for me, I live close to a 900 ft mountain in San Diego and do laps on there and an adjacent peak. Good exercise and great for stress relief after work.
Skyline is hard, but I think way overrated. If you're serious about attempting something like Williamson now in the snow as I see from another thread, Skyline will be no problem for you.
