On October 10, 2014, President Obama designated roughly 346,000 acres of the Angeles and San Bernardino National Forests as the San Gabriel Mountains National Monument. The presidential proclamation prohibits mining or geothermal leasing, except under the Materials Act of 1947 (sand, stone, gravel). Existing operation, maintenance, replacement or modification of water resource, flood control, utility, pipeline or telecommunications facilities within the monument will not be affected. However, expansion or new development associated with these existing facilities may be prohibited by new regulations.

The area will be managed by the Forest Service under the Secretary of Agriculture. Within the next three years, the secretary must prepare a management plan for the area and promulgate regulations for its execution. Stakeholders should consider participating in the rulemaking to protect their interests.

The designation comes after an unsuccessful push by Rep. Judy Chu (D-Calif.) to establish the 615,000-acre San Gabriel National Recreation Area. After several failed attempts, Chu reached out to President Obama to use his legal authority under the Antiquities Act of 1906 to designate the area. The act gives the president the ability to bypass congress in setting aside federal land as a national monument – a designation that gives greater power to the managing agency to regulate uses on the land. This is the 13th time President Obama has designated such a monument under his Antiquities Act power.

Though the designated area excludes some of the more controversial sites encompassed by Chu’s proposed legislation, such as the infrastructure-heavy southwest corner of the Angeles National Forest, and private and municipal properties, it does include the San Gabriel River, several other perennial streams and springs, and other resources on National Forest land. A map of the monument’s boundaries may be viewed here.