AP source: Obama to designate part of San Gabriel Mountains in Calif. as national monument

President Barack Obama is planning to designate 346,000 acres within the San Gabriel Mountains northeast of Los Angeles as a national monument, a step supporters say will ensure better stewardship in one of the nation's most heavily visited forests but worries some local officials because of potential restrictions.

A White House official, speaking on condition of anonymity ahead of Friday's announcement, said Obama's order will ensure the land is permanently protected.

The San Gabriel Mountains are a popular recreation area, and more than 15 million people live within a 90-minute drive. The White House says the designation builds on more than a decade of support for additional protections from various business and environmental groups, as well as members of Congress.

Democratic Rep. Judy Chu sponsored legislation in the House designating the San Gabriel Mountains as a national recreation area, but the bill has stalled in a House committee where Republicans have generally been wary of designations that could limit what activities can occur on federal lands. In explaining her proposal on her congressional website, Chu said the designation would help cities create more opportunities for recreation and improve visitor services.

Obama has used his authority under the Antiquities Act to create or expand 12 other national monuments across the country. White House officials say Los Angeles County is one of the most disadvantaged counties in terms of access to open space for minorities, especially children. For many urban residents, the mountains provide the only available large-scale open space.

Local officials remain concerned about what the monument designation will mean. Los Angeles County Supervisor Michael Antonovich said in a news release Wednesday that the monument designation bypasses local stakeholders. He said it's unclear how the designation will affect water resources, roads and efforts to prevent forest fires.

"We now have more questions than answers, and unfortunately, we will be unable to definitely determine the potential impacts of a designation prior to the president's ill-advised executive order," Antonovich said.

The advocacy group San Gabriel Mountains Forever applauded the coming designation, which was first reported by the Los Angeles Times. Members said that when the land becomes part of a national monument, it receives the recognition and attention it deserves.

"Designating the area as a national monument will ensure its resources are managed properly and protected for future generations to enjoy," Los Angeles Mayor Eric Garcetti said in a news release issued by the group.

The area is already part of the Angeles National Forest, but the rules are more lax about what can be done in a national forest than in a national monument.

For example, new roads can be built and new mines created in a national forest. National monument designations honor existing rights but prevent new drilling and mining while ensuring that historically significant objects are protected.