Introducing the San Gabriel Mountains National Monument; see the map

President Barack Obama has used his authority under the Antiquities Act to establish the San Gabriel Mountains National Monument, setting aside 346,177 acres of Angeles National Forest for permanent protection from development.

The president signed the proclamation at a ceremony at Frank G. Bonelli Regional Park in San Dimas Friday afternoon.

"I can think of no better way to honor our past and protect our future than by preserving the San Gabriel Mountains," Obama said.

The new status is meant to protect the popular area for outdoor recreation and to increase access for local residents, according to a statement released by the White House earlier in the day, which also noted Los Angeles County is one of the most disadvantaged in the nation, something the president addressed in his remarks.

"We heard from the community that for a lot of urban families this is their only big, outdoor space. And too many children in L.A. County, especially children of color, don’t have access to parks where they can run free and breathe fresh air, experience nature, and learn about their own environment," Obama said.

A number of philanthropies have already come forward to support development of the area, according to the White House statement:

"A signature by the President, dedicating or declaring a national monument is just a declaration," said Bill Possiel, president of the National Forest Foundation, which is the nonprofit partner to the U.S. Forest Service. It works to improve community involvement with forests and also administers private donations. 

Possiel says the Forest Service will have three years to develop a management plan to improve services for the area. That'll take a lot of input form state and local governments, community organizations and environmental groups. And it's not clear where the money beyond what's already been pledged will come from. 

"A new national monument doesn't come with additional resources unless Congress decides through the appropriations process they want to dedicate new resources to the national monument," he said. "We won't know that until we're farther along in the national monument planning process."

Victor Garcia and Valente Adame, who have been visiting the area since they were kids, were recently preparing to set off on an overnight camping trip in the Angeles National Forest north of Azusa. They told KPCC they were unaware their favorite wilderness was about to become the country's newest national monument.

"It was definitely a lot prettier. I'd say there's a lot more graffiti now," Garcia said.

"I mean, we bring trash bags to clean up whatever trash we see, but just as much as we can," Adame said.

The new designation means more focus will be put on cleaning up the forest and improving services.

But not everyone is excited about the president's executive decision.

"I don't know what I'm going to do now," said Bob Wagner, who has been prospecting for gold in the San Gabriels since the '70s.

Wagner worried the national monument designation will mean he and his friends will have to pack up their gear.

"As far as I'm concerned, that's illegal. It's supposed to be done by the Congress, and he is acting like a king, potentate, whatever you want to call him, and waving his magic wand," Wagner said.

The new designation won't explicitly outlaw prospecting — that's because it's already illegal. It could, however, increase ranger presence, making enforcement more regular.

It also means more attention on the forest lands as recreation area, Possiel said.

"It changes the way we think about a place. So the forest service will continue to manage it, and we're hoping that as they go forward they'll be thinking in a different way about the San Gabriels than perhaps has been the case in the past," Possiel told Take Two.

Posiel said the $3 million his organization is contributing will go toward engaging community-based organizations to get youth involved and help raise awareness among those that may not be aware of what the San Gabriels have to offer.

Some environmentalists were disappointed the monument did not include Arroyo Seco and Tujunga canyons.

“We were shocked and stunned when we saw the map,” said Tim Brick, managing director of the Arroyo Seco Foundation. “The entire upper watershed of the Arroyo Seco was burnt off five years ago by the Station Fire, and the U.S. Forest Service has done next to nothing to deal with that since then. And now the Arroyo Seco is going to have to compete for the Forest Service's attention and resouces with the more priviliged areas of the Angeles National Forest in the National Monument to the east."

You can see a map showing the newly designated national monument's boundaries below:

This story has been updated.