Powell Butte Trail Maintenance (Friends of Powell Butte)
Powell Butte often gets overlooked in the city of Portland-- it's got great singletrack and depending on where you live, you can ride there and then ride the trails there.
Consider riding your bike there on a Saturday to help out the trails in the park. The Friends of Powell Butte host a monthly trail maintenance day.
Powell Butte Monthly Trail Maintenance
Date: Every 2nd Saturday of the month except August and December -
Time: 9 to 11 AM