A rare California coastal wilderness that served as a training ground for generations of soldiers was designated a national monument Friday in a presidential signing ceremony.

President Barack Obama signed a proclamation that protects nearly 15,000 acres of the decommissioned Fort Ord military base along Monterey Bay. It's the second national monument created by Obama in his three years as president.

About 1.7 million soldiers trained at the former U.S. Army post from the beginning of World War I through Operation Desert Storm. Now, the scenic area is a popular spot for hikers and mountain bikers and home to protected wildlife and plants.

"This national monument will not only protect one of the crown jewels of California's coast, but will also honor the heroism and dedication of men and women who served our nation and fought in the major conflicts of the 20th century," President Obama said in a statement.

The area coming under federal protection will preserve a major swath of the rare Central Coast Maritime chaparral ecosystem, a habitat unique to California. Mountain lions, deer, eagles and the protected California black legless lizard all make their homes at Fort Ord.

The official proclamation signed by the president cites Fort Ord's ecological and historical significance as key reasons for protecting the land.

The undeveloped sections of ancient dunes likely look much as they did to early Ohlone settlers and later to Spanish explorers in the late 18th century whose overland route from Mexico to San Francisco passed through what became Fort Ord.

"The protection of our natural and cultural heritage is essential to providing people with an opportunity to experience the outdoors. It is great to see the administration take this action," said Brian O'Donnell, executive director of the Conservation Lands Foundation, which helped organize support for the monument designation.

The preserve will formally be known as Fort Ord National Monument.

At its peak, Fort Ord spanned a total of 28,000 acres and was declared a Superfund site four years before its official closure in 1994. In 2008, the Army transferred to local authorities some 3,300 acres of the one-time infantry training center, still believed to be littered with unexploded ordnance.

Local officials at the time said they wanted to use the land for housing and expected cleanup of the area under their control to take five to seven years with the help of $100 million from the Army. A California State University campus, many homes and several big box retailers already occupy other sections of the former base.

Initially, a little more than 7,000 acres of the monument already cleaned up will be open to the public, said Bob Abbey, director of the Bureau of Land Management, which will oversee the monument. Another 7,400 acres remain under Department of Defense control as cleanup continues through 2019, he said.

Abbey said the cleaned-up areas pose no environmental hazard to the public. About 100,000 visitors already come to Fort Ord annually, and that number is expected to increase with the monument designation, he said.

A president's power to proclaim national monuments originates in the Antiquities Act of 1906.

President Obama in November designated a shuttered Army fort in Virginia with an important role in the nation's slavery history as a national monument. The site of the decommissioned Fort Monroe was where Dutch traders first brought enslaved Africans in 1619.