Rocky Run Creek originates in Lake Lillian on the south end of Rampart Ridge. Exiting the lake the stream flumes down a narrow crack, cascading a total of 253 feet before flowing through a talus pile. Almost immediately after it drops over another fall of 35 feet before emptying into small but quaint Lake Laura. Though the falls are fairly visible from around Lake Laura, because the majority of the drop occurs within a narrow crack in the cliff band the upper reaches of the falls are difficult to see clearly.
Rocky Run Creek at this point in its course is entirely dependent on snow melt for sustenance and though the small basin above Lake Lillian retains a significant amount of snow into July, once the snow has disappeared the lake level will drop enough that the falls will often dry out entirely (generally by September) until wet weather returns in the fall.
- Lillian Falls is the Adopted name of this waterfall.
From the Snoqualmie Pass summit, head east on I-90 to the Gold Creek exit and follow FSR #4832 signed for Gold Creek. The road passes the turnoff for Gold Creek after a mile, crosses Rocky Run Creek and then begins climbing as a gravel road. After 3.9 miles, bear left onto road #4832-136 (not usually marked). Road 136 is usually overgrown and as of July 2011 there was some nasty rutting right at the beginning that low clearance vehicles may not be able to get over (don't drive a car up it unless you don't mind seriously scratching the paint). Follow road 136 for just under 2 miles, bearing right at a fork at the halfway mark, to a large parking area at a tight switchback in the road. Find the trail at the back of the parking area and follow it up the valley through a clearcut and then into the forest, encountering Rocky Run Falls after about half of a mile. The trail then climbs very steeply to the top of Rocky Run Falls and briefly levels off again before climbing steeply above the second headwall. After about 6/10ths of a mile the trail reaches a junction, head left to reach Lake Laura. Lillian Falls can be seen from the shore of Lake Laura in many places, the best views being near the outlet (this may require scrambling around in the woods to find a clear view).