Heart Lake / Whistle Lake Professional Review and Guide
"Rooty, rocky, hard-packed trails and roads invite mountain bikers to wander among old growth and alder, ferns, mosses, and wildflowers. You'll find some level stuff here, but not too much, and that's part of the fun. Middle-ring climbs, low-ring climbs, and even some hike-a-bikes are rewarded with sometimes speedy, sometimes jarring descents. Search around for views at the crests of the climbs; you'll love what you see.
There are a few descents riding down to Heart Lake Road excessively rutted, to the point where I was walking my bike downhill, but the vast majority of the trails were quite rideable, quite beautiful, and quite fun. Your conduct on the trails will determine the future of mountain biking in this beautiful, challenging area. Scenery: Beautiful lake overlooks, deep woods, San Juan Islands views form the high points on the trails, distant views west, south, and east form the top of Mt. Erie (road only)."