Drive on Highway 2 east towards Stevens Pass. Just after the Iron Goat site turn right. Cross the railroad tracks and turn right, following a narrow dirt road to the trailhead.
Surprise Creek Trail is deceptively difficult as it winds its way up the valley. At roughly 4 miles the trail will start to head with the creek directly up the ridge line where you will cross the lip. Another quarter mile of flat terrain and wrapping around the creek and you will reach Surprise Lake.