Lake Valhalla via Smithbrook Trail is a moderate almost 7-mile hike along a relatively smooth trail to astounding lakeside views of Lichtenberg Mountain.
The Smithbrook trail starts off with several switchbacks, then continues up to Union Gap where it meets the Pacific Crest Trail. Turn south (left) at Union Gap and continue hiking until you reach the gap between Mount Lichtenberg and McCausland, where you get a first glimpse of Lake Valhalla.
Just before reaching the gap, a boot trail follows the ridge up to an old lookout site at Mount McCausland. Less then a half a mile and 600 feet of climbing and you will reach the top, where you will have a great view of Glacier Peak to the north. There are lots of huckleberries in the meadows along this trail.
Pass over the gap and descend to Lake Valhalla. There are a number of overnight campsites and a couple of backcountry toilets at the lake, although campfires are not permitted. There is a very pleasant sandy beach at the lake as well, which is perfect for lunch and relaxing in the summer.
This is also a great hike to see fall colors.