PASADENA, Calif. (NewsNation Now) — Firefighters prevented a Southern California wildfire from damaging the historic Mount Wilson Observatory, which played a pivotal role in confirming in the early 20th century that galaxies exist outside the Milky Way.

The Bobcat Fire in the San Gabriel Mountains northeast of Los Angeles came within 500 feet of the observatory Tuesday, but efforts like controlled burns to clear fuel, water drops and clearing brush helped protect the historic building, Angeles National Forest officials said on Twitter.

“While there is still much work to be done in southwest and in the northern sections of the fire, your firefighters did incredible work around Mt. Wilson today,” they said overnight.

As of Wednesday morning, the fire had burned more than 44,000 acres and was only 3% contained but the flames were calmer according to the Angeles NF.

Mount Wilson rises to an elevation of more than 5,700 feet (1,740 meters) about 15 miles (24 kilometers) northeast of downtown Los Angeles.

The observatory was founded in 1904 by legendary astronomer George Ellery Hale, who sought to take advantage of Southern California’s then-clear skies.

The observatory made solar observations before Hale set his sights on bigger things — first a 60-inch reflector telescope that began being used in 1908 and then a 100-inch telescope that saw first light in 1917. In their day, they were successively the world’s largest telescopes.

In 1924, astronomer Edwin Hubble used the larger of the two telescopes to confirm theories that galaxies exist beyond the Milky Way and by 1929, was able to show, along with colleague Milton Humason, that the universe was expanding.

The famous telescopes and solar observation towers remain on the peak, along with modern astronomy instruments that are used now. Nearby, there is a forest of TV and radio broadcast towers serving the greater Los Angeles region.

More than 16,600 firefighters are battling over two dozen major California wildfires, while other crews work to beat back flames in Oregon and Washington state. The smoke from the fires is fouling air across the American West.

All national forests in California are closed until Sept. 21 per the USDA Forest Service. The U.S. Forest initially shut down eight forests Sept. 7 before expanding the order to all of California’s 18 national forests on Sept. 9.

This story is developing. Refresh for updates.

The Associated Press contributed to this report.