Exploring the mines & water tunnels of Las Flores Canyon above Altadena, CA.
Las Flores Canyon (Canyon of the Flowers) sits right next door to the popular Echo Mountain Trail at the top of Lake Avenue in Altadena.
But while thousands of hikers ascend the Echo Mountain Trail every week, only a handful venture into Las Flores Canyon.
Las Flores Canyon is located past the stone gates of the old Cobb estate. A wealthy lumber magnate, Charles H. Cobb built his estate above Altadena’s old poppy fields in 1916.
After his death in 1939, the home passed through several owners before being razed 20 years later.
The Marx Brothers (stage and film stars from the early 1920s to the late ’60s) , bought the 107-acre tract in 1960 and planned to sell it for use as a cemetery. Fortunately, a group of local ecologists stepped in, purchased the land and turned it over to the Forest Service in 1971 as a nature preserve.
The Las Flores Water Company, incorporated in 1885, is the oldest of three small water companies serving the Altadena foothills community.
An old water company map dated 1906 shows a dozen mines/water tunnels in the canyon. Note: These would actually all be classified as being mines not tunnels but since many of them are officially labeled as tunnels on the old company water map, I’ll often use both when describing them here.
Most of the mines are well hidden and hard to find. This one was almost fully closed off due to all the erosion and flooding that’s occurred over the years.
This one had a bigger opening but didn’t have much depth to it.
Gold mining activities in the canyon started around 1881 but soon merged with tunneling for irrigation water which was more profitable. Only one of the tunnels within the canyon (tunnel #8) is still in operation. Because of excessive fluoride and uranium, it has not been used for drinking water since 1974 and is now used only for reclamation purposes. Another one of the mines is named after the founder of Rand McNally & Company. Andrew McNally’s old estate is located nearby at the intersection of Mariposa and Santa Rosa Streets.
Tunnel #4 is one of the best mines to explore within this steep, overgrown canyon.
Inside Tunnel #4 which is the longest of the 12 mines within the canyon at 837ft.
There’s about a foot of water at the beginning of the mine…
…which tends to scare most people off from exploring it, but once you get in a little ways, the water recedes and it begins to open up.
Like other mines located in the San Gabriel Mountains, calciferous deposits can be found in numerous sections of tunnel #4.
There are several drifts that branch off from the main adit…
…but all of them dead end at some point.
Fools gold shimmers deep within the mine.
Veiny
This is the only timbered stabilizer within Tunnel #4.
Most of the water found inside is generated from springs located within the mine.
Cave Pearls vs Hard Rock
After spending 30 minutes inside tunnel #4…
…it was time to go back out into the light and make my way to work. On the hike back to my car, I passed through a section of the trail with sage growing on both sides of the path. Thank you Las Flores Canyon for the perfect ending to an incredible morning.
Protecting and preserving historic, sacred, and sensitive sites should be practiced by all. Locations, directions, and names to some of the places found on this site are not listed, please don’t ask for them. Tread lightly, leave no trace and always respect the wonder that surrounds you.
