Because of its close proximity to Snoqualmie Pass, Interstate 90 and several cirque on both sides of Rampart Ridge, the lake is a common area for hiking, swimming, and fishing rainbow trout.

[1] Rocky Run Creek outflows from Lake Lillian into neighboring Lake Laura and continues toward NF road 136 on Rampart Ridge Backdoor.

Lake Lillian sits on the eastern aspect of the meadow valley it shares with Lake Laura on the eastern skirt of the southern aspect of Rampart Ridge.

The parking at Lake Lillian Trail is adequate for 20 vehicles.

[4] The trailhead is approximately half mile from the start of Rd 4934 off of Forest Road 4832.