Happy Lake Ridge Trail is part of a complete loop-route, 17 miles long. It’s a 3,000′ climb from the Happy Lake Ridge Trailhead, topping out in about 3 miles, and then a subalpine walk along a very broad & mild, semi-open ridge-system; almost rolling plateau-like. There is standard camping at Happy Lake, which someone once called wet and buggy (weather-related?), but is set in a fine geology-exhibit & invitation to explore. The trail makes a tee with the Aurora Divide Trail at about 7.5 miles, and then reaches its end at Boulder Lake, at 9.5 miles. Then it’s downhill for the rest of the loop (partly on the low-key, antique road).
It’s of course not necessary to hike the loop around. The first-night camp can be a base, and then reverse back on the same ground to come out. While lacking big-drama, the trail has interests, peekaboo views, and has an off-the-beaten-track feel. The Lake camp does have drama nearby, as does the not-really-a-peak Lizard Head Peak area, a mile west. For those tolerant of brush & boughs way-finding, the Happy Lake Ridge-Baldy Ridge Saddle just beyond the Lake showcases a pair of seldom-photographed plunging watersheds.
The social ambiance picks up sharply as one drops down off the cruising-ridge into Boulder Lake, and continues to amp-up all the way down to the skinny-dipping at Olympic Hot Springs. Really only large sulfur-smelling puddles, folks are overwhelmingly considerate here, and one sees decorously clothed families as well as the clothing-optional groups – who do not make a practice of parading. The small pools are widely-spaced and the brush & trees provide privacy. If this is what you wanted, just drive on by the Happy Lake-country pullout, park up at the deadend trailhead to join the main herd. In fact, it’s a go-to scene at the Hotsprings that rates at least a walk-by … but for a change of pace, the Happy Lake Ridge Trail is the real deal.
Crystal Ridge Abandoned Trail shortens the loop-route some, but not dramatically. What it does more emphatically, is it cuts the Boulder Lake scene, and the Boulder Lake Trail out of the loop-experience. It connects back with the standard route, behind the old car-campground at Olympic Hot Springs (which is now official backcountry, via 2.4 miles of the Olympic Hot Springs Abandoned Road). The old trail-tread is quite plain on the hillside behind the campground, but is less detectable on the open ridge-crest where it connects to the Happy Ridge Trail. Upper Crystal Ridge itself, though, is very cleanly delineated, open, and easy to follow. The south side of Crystal puts on a fine talus-slope display, from the trail climbing up out of the Boulder Lake tarn.
At the Aurora Ridge Trail intersection, 7.5 miles up from the Happy Trailhead, it is 8.9 miles to the Storm King Ranger Station Trailhead, via Aurora Divide Trail and Barnes Creek Trail, for a through-hike of 16.4 miles. Continuing on Aurora Ridge, there is then the option to through-hike 8.9 most-different miles past the Aurora Divide junction, to the Aurora Creek Trailhead via Aurora Creek Trail, for the same distance of 16.4 miles. Storm King is part of the big-time Barnes Delta Recreation Area complex, while Aurora Creek is a zip-past-it paved pullout.
Finally, the whole of Aurora Ridge can be hiked from (or to) Happy Lake Ridge Trail, using the far-west Aurora Ridge Trailhead, a distance of 24.3 miles.