Umtanum Canyon is one of my favorite spring hikes. Located at a low elevation deep in the rain shadow of the Cascades, the canyon is almost immune to any dampness occuring in Seattle.
To get there, drive east on I-90 to Ellensburg, then south on the Yakima Canyon road to the Umtanum Recreation area parking lot.
Cross over the Yakima River via the suspension foot bridge, and follow the trail through a patch of brush, over some railroad tracks (actively used, look around before crossing), and into the mouth of Umtanum Canyon.
At first the trail is easy going as it travels up the broad, meadowy floor of the canyon. If you're used to hiking dense, drizzly Cascade forests, the wide open spaces, blue skies, and sunshine will have you raving. The colorful cliffs of lava forming the walls of the canyon give the area almost a Southwestern ""canyon country"" feeling. The meadows are turning green with spring growth and flowers are beginning to bloom, some buttercups and balsamroot. The lower part of the canyon is almost treeless, but here and there grow scattered groves of aspen and cottonwood, pale green with newly budding leaves.
After a mile or so, the trail splits, and the ""correct"" trail crosses the sizable Untanum Creek. Finding the correct points to cross the creek is the major navigation problem of the canyon; the ""false"" trails that don't cross invariable look better at first, but then fade out in brush. Naturally, the impoverished public land owners (BLM and/or wildlife refuge) have provided no signage or much trail maintainence for that matter. A second crossing occurs a mile later; the correct trail drops down a steep bank, crosses the creek on logs, and resumes on the other bank next to a spacious campsite.
Beyond the second crossing, the trail steadily deteriorates. The walls of the canyon close in and the floor becomes narrower and brushier. At places, lichen-covered lava cliffs loom right over the trail. There's a lot more trees along this stretch, many chewed by beavers; a few pines and firs appear on the shady south slope. The trail passes a series of creekside meadows that positively beg for a picnic or even an overnight camp. Eventually the trail drops down to the edge of the creek at a gravel bar; just a bit further is the obscure third crossing point, marked by a very wobbly and marginal foot log. Casual hikers should turn around here.
If determined and a bit masochistic, you can continue on all the way to Durr road, another 2 to 3 miles upstream. The old trail (once a fair-sized road) has been wiped out in most places by floods. There exists a faint but continuous path most of the way, but it will challenge your route finding skills to follow it. There's a lot of scratchy brush and six or so creek crossings, some a bit tricky. The route is not all bad, however; there's a pleasant stretch where an intact portion of the old road passes a small, broken-down cabin in a meadow and some large ponderosa pines.