Meetup.com
Corvallis area: https://www.meetup.com/cities/us/97339
Adventures Around Oregon - Corvallis, OR - https://www.meetup.com/adventures-around-oregon
Corvallis Outdoors Meetup - https://www.meetup.com/corvallis-outdoors-meetup
Mid-Willamette Valley Social Meetup - Lebanon, OR - https://www.meetup.com/mid-willamette-valley-social-meetup
Willamette Valley and Mid-Coast Walkers - Corvallis - https://www.meetup.com/willamette-valley-and-mid-coast-walkers
Stop and smell the flowers hiking group - Lebanon - https://www.meetup.com/stop-and-smell-the-flowers-hiking-group
Rise and Shine, Morning Walk - Albany - https://www.meetup.com/rise-and-shine-morning-walk
Willamette Wanderers Bicycling Enthusiasts - Albany, OR - https://www.meetup.com/willamette-wanderers-bicycling-enthusiasts
Corvallis Gaming - https://www.meetup.com/corvallisgaming