Snowgrass Flat is a gorgeous destination in the Goat Rocks Wilderness, with a lovely wide meadow and excellent views of surrounding peaks and wildflowers in season. It makes for a lovely day hike and there are also campsites if you'd like to turn your trip into an overnight.
Soon after leaving the trailhead, you'll notice the equestrian trail to the left, which heads to the equestrian parking lot. Continue on the main trail. The trail begins mostly gently for the first section, crossing a few streams and traversing a forested hill, before crossing Goat Creek at a bit after 1.5 miles. Soon after, the trail begins to climb more seriously. As you climb, you'll start to see more views, including Mount St. Helens. At 3.6 miles, you'll reach a junction. Head left toward Snowgrass Flat. (Turning right takes you toward the Pacific Crest Trail.)
Continue for another 0.7 miles to Snowgrass Flat. Along the way, watch for campsites. Be sure to camp in established sites, and not on the meadow. You can also continue on another 0.8 miles to join the Pacific Crest Trail and enjoy even more views and meadows. If you're not exploring farther, return the way you came.