Lower Aero Lake Trail

This is an out-and-back from the upper Lady of the Lake access to Lower Aero Lake’s west shore. The mapped corridor is about 5.7 miles each way; this entry uses 11.3 miles round trip. Reports give different distances, so carry an offline track and plan on a full day—around 7–8 hours. The lake sits nearly 10,000 feet high, about 1,270 feet above the access, and the route rises and falls along the way. This is a much bigger outing than the separate Lady of the Lake walk.

The upper trailhead is reached from Lulu Pass Road. The path starts among trees, then follows the Zimmer Creek drainage with occasional creek views. A poorly marked fork near Star and Zimmer creeks is the key route-finding decision; trip accounts describe crossing Zimmer Creek at a cairn to stay on the Aero Lakes line. Use a mapped track rather than following whichever creek branch looks easiest. This route stops at Lower Aero; continuing toward Upper Aero is a separate extension.

The final 0.75 to 1 mile climbs roughly 900 to 1,200 feet over loose rock and scree. Tread can fade into rocky gullies, and the altitude adds effort. Reaching the water can involve a steep rock band where snow may linger. A trip report documents a serious fall on that descent, so stay on the mapped route and don’t downclimb the band just to reach the water.

Lower Aero covers about 187 acres at 9,995 feet. Its rocky shore and small islands sit beneath Glacier Peak, Mount Villard and The Spires. One camp report also describes two waterfalls and a reflecting pond near the lake, but that view is from a lakeside camp and isn’t guaranteed from every stopping point on this route.

The separate Lady of the Lake walk is about 3 miles round trip from its lower access. It makes a shorter outing but doesn’t reach Lower Aero; use it if you want the nearer lake without this route’s high, rough final climb.