Lookout Mtn

Mount Baldy, California 91759

Lookout Mtn

Lookout Mtn. Professional Guide

Detailed Trail Description from our Guidebook

"Lookout Mtn., a seemingly minor bump on the south ridge of Mt. Baldy, plays an important role in the history of science. In 1915, a fire lookout was constructed on the summit to take advantage of the commanding views. In 1926, Albert Michelson conducted a groundbreaking experiment here to measure the speed of light. He placed a prism on Mt. Wilson and a large mirror on Lookout Mtn. The United States Geodetic Survey team surveyed the distance between the two peaks with unprecedented accuracy. By bouncing a beam of light from the prism off the mirror and carefully measuring the round trip travel time, he determined that the speed of light is nearly 300,000 kilometers per second or about 670 million miles per hour. In 1927, a windstorm destroyed the fire lookout and now all that remains are some concrete pilings."

More Lookout Mtn. Professional Guides

Detailed Trail Descriptions from Our Guidebooks

Afoot & Afield Los Angeles County (Wilderness Press)
Jerry Schad
View more trails from this guide book
"Lookout Mountain, a prominent bump on the south ridge of Mount San Antonio, was named after “Baldy Lookout,” a wooden tower constructed there during 1915-16 and used every season until 1927." Read more

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Trail Information

Mount Baldy
Nearby City
2,400 feet
Elevation Gain
Trail Type
Skill Level
6 hours
Angeles National Forest
Local Contacts

Activity Feed

Dec 2018