Lampier Lake / Gunsight Pass Professional Review and Guide
"Like most of the alpine lakes in Colorado, Lamphier Lake is a glacial tarn that was scooped out of the surrounding rock during the last ice age. The well-protected lake lies just below timberline, and is surrounded on three sides by Broncho Mountain, Square Top Mountain, and Fossil Mountain. Lamphier is particularly scenic early in the morning when Square Top Mountain is reflected from its shaded, mirror-smooth surface; if you are interested in seeing this morning spectacle you will find several fine camping sites in the trees along its eastern shore.
Although Lamphier lies in a bowl of granite and schist, the ridge above the west side of the lake is capped with an unusual layer of limestone. Looking up at the ridge you can easily distinguish the difference in color and texture between the granite and its sedimentary overburden. Most of Colorado was once covered with sedimentary rock, but in the 45 million years since the Rocky Mountains were uplifted most of the overlying sedimentary deposits have eroded away. The ridge above Lamphier Lake is called Fossil Ridge because, like most limestone formations, it is rich in fossils."