It's about a ten-mile round-trip, but a summer hike up to Goat Lake in the Central Cascades will reward you with a glacially-colored mirror of snow-clad crags and distant waterfalls. An easy day-hike from Seattle (if you get up early), it's also just low enough in elevation so that the trail is usually snow-free by late spring.
The day I went, my friend and I had the trail almost to ourselves...Switchbacking up through the dark woods, the roar of McIntosh falls lets you know you're almost at the top...and then you emerge from the woods into the lake-filled clearing--ethereally colored by the glacially-ground rock particles in the water...
We met a couple of guys who'd spent the previous night camping above the alpine lake. Then a crew of Forest Service summer workers arrived, with good spirits, ready advice, and machetes for trail-maintenance.
It's about a 1hr45min drive to the trailhead from Seattle.