Edgar McGregor

The Eaton Canyon Conservation Group set out to remove a large castor bean grove located on the east side of the equestrian area this past Saturday, October 14, 2023. With a total of 12 volunteers in tow, Conservation Chair Max Yasuda began at 9:00 AM as a partial solar eclipse neared its maximum point. With the sun being unable to heat the ground, the crew hacked away at several huge, 30′ tall castor bean plants. Within the hour, the trees came down and were being hauled away. Other volunteers spent time carefully pulling the seeds off the castor beans to dispose of them properly. This particular area had been mired in the castor bean species for many years, and native species were nearly entirely choked out.

According to Conservation Chair Max Yasuda, this particular area is important as it is a “wildlife corridor, allowing animals such as mountain lions and bobcats to travel between the city and the mountains.” 

Castor beans, also known as Ricinus communis, are native to northeast Africa in Ethiopia and Somalia. They have been cultivated in many other regions of the world and are incredibly invasive. Castor beans grow quickly, reproduce widely and rapidly, soak enormous amounts of water out of the soils, and can lay waste to the biodiversity of any native ecosystems they are introduced to. Following the landfall of Tropical Storm Hilary in Southern California in August, these invasive castor bean plants exploded in Eaton Canyon. Several hillsides are completely covered in them. Volunteers have been doing their best to keep them contained to certain areas that require crews to handle, but they are growing faster than we can remove them.

If you would like to help, please join the next conservation group meetup in November. You can sign up here.

It was a chilly, clear night in Eaton Canyon as the first Pacific rainstorm of the season approached. A light breeze rustled some Douglas Fir Pines on Mount Wilson while the skies overhead offered incredible views of the heavens. The moon was nowhere to be found. A large band of milky light dotted with secrets not yet discovered by humankind stretched high across the sky from one horizon to another. The year is 1923, and a certain astronomer on Mount Wilson is about to give all of humankind a reminder of just how small and insignificant we humans are.

Inside the brand new 101″ Mount Wilson Observatory Telescope, famed astronomer Edwin Hubble was peering into the night sky. He was aiming for a small cluster of light rising in the northeast over Mount San Antonio. On this night, Edwin Hubble was using a new method of measuring the distance of the stars called Leavitt’s Law. Its creator, Henrietta Swan Leavitt, was a scientist at Harvard who had studied a unique type of star called Cepheid variable stars. In 1908, she discovered that this type of star undergoes regular and predictable variations in brightness over time. By observing the period of a Cepheid variable star, astronomers could determine its intrinsic luminosity, and by comparing it to its apparent brightness, they could calculate the distance to that star. These stars have since earned the nickname “standard candles.” 

All around the world, astronomers who caught wind of this discovery began searching for those stars to calculate the true distances to them from Earth. Over the next 15 years, it became clear that the Milky Way was some 20,000+ parsecs in diameter. Edwin Hubble was one of those astronomers, and on the night of October 6, 1923, he discovered something odd. This method of determining the distance of the stars was seemingly not working for the small inconspicuous cluster he was staring at. His calculations showed that the Andromeda Nebula was 275,000 parsecs from the Sun, much further away than any Cepheid variable star previously discovered. After further investigations and confirmations, it was determined that he was not in error. Upon this discovery at Mount Wilson, Edwin Hubble realized that the nebula he was looking at was in fact the Andromeda Galaxy, a galaxy both different from our own and 250 million light years away. Before this discovery, scientists only had proof that the Milky Way existed, and nothing else. Now, we have proof that the Universe is far, far bigger. Henrietta Swan Leavitt died in 1921, never getting the chance to see her work completely reshape our understanding of the Universe. 

Eaton Canyon has a long history of water, homesteading, and tourism. However, its most significant contribution to the world is that it was here where we discovered the cosmos was incomprehensibly large. It was here atop Eaton Canyon that humankind once again was reminded that we are nothing against the grand scale of everything there is. In this age of fast moving headline news, pointless conflicts, and political drama, such a revelation is worth dwelling upon. 

PBS produced a short documentary at Mount Wilson that you can view here.

The 2022-2023 water year in Eaton Canyon has ended as one of the most impressive water years of the past century. A copious number of storm systems well spread out throughout the entire season dumped a grand total of 4-5 feet of rain. In the past 116 years, only 2005 was able to drop more rain in Eaton Canyon. Included in this astounding year was well over 10 feet of snow on the highest peaks of Eaton Canyon, a landfalling tropical cyclone interrupting a hot summer, and absolutely no destructive flash flooding of any kind throughout all 12 months. Following the driest water year on record in 2021, in which Eaton Dam picked up only 5.63″, as well as the single longest, hottest, most extreme summer ever in 2022, the biological features of Eaton Canyon were suffering greatly. After 23 years of megadrought conditions across the western United States, this is precisely what Eaton Canyon needed to recover. 

Contrary to popular belief, megadroughts can not be ended in a single year even if record amounts of precipitation falls. Megadroughts are defined as ecologically destructive events in their own right, as they can cause entire species to go extinct, ecosystems to collapse, and ecological biomes to shift dramatically. While short-term extreme droughts can be sudden, megadroughts are relentless and span decades. Megadroughts can actually allow for native species to respond to changing climates. A minimum of 3 consecutive wet winters and cooler than average summers are needed to repair those damaged ecosystems and food chains. Some areas may require 5 such years to fully recover. This isn’t about reservoir levels or how good of a ski season it was, this is about the health of the entire ecosystem of this region of the world. In this era of rapid climate change, such a period of relief is less and less likely. Most summers in the 21st century are oppressive and lengthy. Even 2023 was an extremely hot summer for Southern California, with the July-August period being the second hottest July-August period ever behind only 2022. That being said, the canyon was struck by a landfalling tropical cyclone in mid-August that dumped 5″ – 7″ of drought-relieving rainfall. These tropical downpours kept the gains of the previous winter alive. More on Tropical Storm Hilary’s impact on Eaton Canyon can be found here. 

Timeline of the 2022-2023 Eaton Canyon Water Year: