A good ride for a beginer on a Mt. or cross bike. There is some good single track on side trails but most are closed to bikes. The people of Portland make a stink when they find you ridding them so watch out . Fire lane # 1 and # 3 are great down hills but are short. You can shuttle them if you have a car or truck.
If you can find downtown Portland Oregon You can find the Trail. Head out of town on Burnside drive. On NW 23rd st turn R and then L on Thurman Rd. Head up the hill to Forest Park and the trails. The trail head is only about 3 miles from downtown Portland.
http://www.singletracks.com/item.php?c=1&i=1008