Not real challenging but can be real fun. Explore the spur trails.
This is a relatively easy trail with some fun, more challenging singletrack off the main trail. Follow under the powerlines from the parking area for about a mile and look to the right for a trail heading into the woods. Lookout for 4-wheeled vehicles until you get into the safety of the forest. Also check out some more trails across Novelty Hill road about .25 miles to the east.
How to get there:
From Seattle, head East on SR 520. Follow it to the end and follow the signs for Avondale Rd. Follow Avondale Rd. for about 2 miles, then turn right onto Novelty Hill Rd. After about 5 more miles you will see a small parking area under some powerlines. Park here and follow the powerlines to the trail.
There is a lot of construction and new housing in this area. They are saving some of the trails, but a lot are being wiped out for million dollar homes.