Over used but never out of fun. Old reliable for Seattle residents.
This is by far the most popular trail in the Seattle area. Its proximity to the city and challenging singletrack make it a mecca for many riders. There are two fire roads from the parking lot. Head up the road on the right. After about 2.5 miles of climbing, you will come to a fork in the road. Keep left and after another .5 miles you will see the Preston trailhead on the right. Follow this trail for about 4 miles and you'll come out on another fire road. Turn left down the hill and at the fork, turn right and continue down the hill. After some fast downhill and a short climb, look for the Timberline trailhead on the right. Follow this trail for another 3 miles then turn left on the fire road back down to your car.
How to get there:
From Seattle take I-90 East to exit 25. Follow Hwy 18 South for about 5-miles (just past the summit). The parking lot sneaks up on you on the right.
If it's been raining any time recently, don't even think about riding it. it is closed Oct.