About 75 miles northwest of San Diego, beyond the view of much of the mainland, the rugged and remote Navy outpost of San Clemente Island remains a mystery to most Californians.
For nine decades, San Clemente Island, the southernmost of the eight Channel Islands, has been owned by the Navy and is largely inaccessible to civilians. Throughout this time the volcanic isle’s sprawling shoreline and rolling hills have served as a crucial military training ground where U.S. troops detonate grenades and fire heavy artillery. It’s also the Navy’s last live-firing range for ship-to-shore bombardments.
So, in late July, few noticed when a catastrophic wildfire swept over more than 13,000 acres of the island outpost. Between July 24 and July 30, the blaze scorched more than a third of the island, damaging more than nine miles of high-voltage power lines, including more than 160 utility lines and a transformer, according to Navy documents.
The fire also swept through parts of the island that have rare habitats for sensitive plant and animal species found nowhere else, such as the endangered San Clemente loggerhead shrike, a carnivorous songbird.
The conflagration left the southern end of the island charred, and numerous Navy buildings without power.
It is expected to take at least a year to restore electricity to those facilities. In the meantime, the Navy will rely on diesel-powered backup generators to maintain communications for its operations, as well as for Federal Aviation Administration air traffic control functions and Coast Guard search-and-rescue missions.
Navy spokesman Kevin Dixon said the fire may have been caused by live-fire military exercises in the so-called shore bombardment area, although it remains unclear what type of training might have sparked the blaze. After two years of above-normal rainfall, Dixon said, there was much more grass to catch fire. No one was injured or evacuated.
“We did have training going on there where there was bombardment,” Dixon said. “So I can’t definitively say that it is, but, just looking at it logically, it may be related to this.”
Members of the California National Guard’s 79th Infantry Brigade prepare to fire a mortar round during training exercises on San Clemente Island in July 2024.
(Spc. William Franco Espinosa / U.S. Army National Guard)
Just before the fire, several units of the California National Guard had been on the island for military training exercises that included the firing of howitzer shells and mortar rounds. The military units posted photos and videos of the exercises on social media.
California National Guard spokesperson Lt. Col. Brandon Hill said guard members did not spark the fire.
“If a fire would have started because of those training rounds impacting it would have been immediately reported to range control,” Hill said. “We completed all training on July 23rd and cleared the training areas with no issues.”
NASA’s Worldview tool, which publishes daily satellite imagery and wildfire data, detected a possible wildfire on San Clemente Island around 5:30 a.m. July 24.
Previous reports commissioned by the Navy have found that weapons testing on San Clemente Island increases the likelihood of devastating wildfire and imperils some of the island’s species. In a 2009 environmental assessment, a Navy contractor concluded that most fires were the result of military training, and about half occurred on the southern end of the island in the ship-to-shore bombardment zone.
In the past, the Navy has restricted the use of live ammunition during the wildfire season to curtail the risk of these disasters. No restrictions were apparently in place around the time of the July wildfire.
“If there was some type of fire danger then the units would not have been allowed to train, but that did not occur,” Hill said.
Despite decades of military bombardment, the island remains home to a variety of native plant and animal species. The island’s mosaic of shrubs and grasslands provides habitat for mice, lizards, foxes and numerous birds. Bald eagles have also been spotted.
In recent decades, the Navy bolstered funding for environmental conservation.
Its forces eradicated herds of voracious feral goats that had been brought to the island years ago, and they restored some of the native flora. The Navy also launched captive breeding programs for threatened and endangered species, which significantly boosted their numbers.
The Navy has also reduced the amount of pollution generated by its diesel power plant by installing wind turbines in the late 1990s.
The turbines, which are located on the northern part of the island, were not affected in July’s fire. However, the Navy will be seeking contractors to repair damage to island’s transmission system and power grid.
Last year, the Navy and U.S. Fish and Wildlife Service celebrated delisting the San Clemente Bell’s sparrow and four plant species — the largest group delisting from population recovery in the 50-year history of the Endangered Species Act.
However, several species, such as the San Clemente loggerhead shrike — a robin-sized predator known as the “butcher bird” — remain on the brink of extinction, with just 14 known to be alive.
During July’s fire, Navy personnel moved captive breeding cages as a precaution, although these facilities were not ultimately damaged, according to Dixon, the Navy spokesman.
The Navy has also found hundreds of ancient relics from the island’s original inhabitants.
An outcropping of volcanic rock, San Clemente Island was formed by eruptions millions of years ago. It had once been inhabited by a prehistoric Native American tribe, believed to be related to the Tongva who occupied present-day Los Angeles.
In the 1500s, Spanish explorers landed on the island and conducted trade with the tribe. By the early 1800s, however, the Indigenous population could no longer be found on the island. Some say they departed their ancestral home with Spanish missionaries.
Under President Theodore Roosevelt, the Navy acquired San Clemente Island in 1934. Workers built barracks, roads and piers, setting the stage for the island to become the Navy’s premier weapons testing ground. The naval island is where the Navy developed the Higgins boat — the pivotal landing craft that ferried troops to the beaches of Normandy during the D-day invasion.
Members of the California National Guard’s 1st Battalion, 143rd Field Artillery, fire an M119 howitzer during military exercises in July 2024 on San Clemente Island.
(Spc. William Franco Espinosa / U.S. Army National Guard)
