I went to Oregon State and loved it there.
Siuslaw National Forest is within biking distance, ~15 miles to the bottom of Mary's Peak or 25 miles to the top.
McDonald Research Forest for shorter day trips North.
Alsea Falls are ~40 miles south for another nice destination.
Willamette National Forest to the East if you want to go a bit further and get some snow and bigger wilderness.
After passing through Bozeman once and Missoula twice, I have to second
>>618010 's opinion.
Missoula is a hipster breeding ground. If that's your thing, great, but holy shit.