San Gabriel Mountains National Monument Plan Nears Completion

Cloudy mountain landscape view

Update (06/13/2018)

The Forest Service has received seven (7) eligible objections regarding the San Gabriel Mountains National Monument Plan (SGMNM) Plan. The publication date of this notice initiates a 10-day period during which individuals or organizations may file a request to be interested persons regarding any of the filed objections, pursuant to 36 C.F.R. §219.57. Interested persons can participate in resolution meetings between the objectors and the Forest Service. To file as an interested person, individuals and/or organizations must have commented during a previous formal comment period for this plan amendment. View filed objections and instructions for filing as an interested person.

The Final Environmental Assessment (EA), draft Decision Notice, and Finding of No Significant Impact (FONSI) for the San Gabriel Mountains National Monument Plan are complete. The final EA presents the environmental consequences of three alternatives analyzed in detail, including a no-action alternative. The proposed monument plan respects and conserves the significant, unique landscapes, vistas and features of this special area, while it will continue to allow existing land uses and provide the experiences, jobs, and services that boost the local economy. The plan will provide guidance for the Angeles National Forest to manage the area’s unique ecological, social, and cultural resources for many years to come. 

Objection Period

According to federal planning rules, the next step is to offer an objection period to provide those interested in or affected by this action an opportunity to object to the proposed Monument Plan prior to a final decision being made. The forest supervisor of the Angeles National Forest will decide whether to amend the land management plan as proposed in Alternative 3 of the environmental assessment or make adjustments based on objections received during the objection period.

The 45-day official objection period began on April 20, 2018. Objections were only accepted from those who have previously submitted substantive formal comments specific to the proposed plan amendment during any previous public comment period.

A copy of the final EA and decision notice/FONSI is available at the Angeles National Forest Supervisor’s Office and on the project website.

Please contact Rachel Smith, Forest Supervisor (Acting), (626) 574-5215, for additional information.  Printed copies of any documents are also available.

Plan Development

President Barack Obama designates the San Gabriel Mountains National Monument on October 10, 2014, at Bonelli Park in San Dimas, CA.

As a part of the planning process for the monument management plan, the Angeles National Forest began public engagement efforts in 2015, including direct engagement with various stakeholder groups, public agencies, and individual members of the public. Outreach included a number of organizations representing underserved communities, as well as the San Gabriel Mountains Community Collaborative. Formed in 2015, this group includes 46 community representatives from the public, elected officials, and non-profit and private organizations who advocate for investment in and sustainable management of recreation infrastructure and natural resources to benefit all communities in the area.

Formal scoping for the environmental assessment began in mid-2015, encompassing approximately 3,200 interested parties. The Forest received over 900 responses, with 1,545 unique comments and concerns. The agency used this feedback to help develop a Draft Monument Plan and Draft Environmental Assessment (EA) in 2016. Over 300 responders with over 1,000 unique comments and concerns were received during the public comment period. Alternative 3, currently the preferred alternative, was developed, in part, as a result of this public feedback.

This management plan provides direction to generate additional transit and access opportunities to the Monument, promote jobs and sustainable recreation, protect biological and cultural resources, improve visitor services and conservation education, and encourage collaboration and partnerships to achieve these ends.


On October 10, 2014, the San Gabriel Mountains National Monument was established by Presidential proclamation, which:

  • Designated 346,177 acres of existing Federal land.
  • Described the historical, natural, and cultural significance of the features within the area that warranted the special designation.
  • Directed that certain uses continue, including Tribal rights to use the lands according to their cultural traditions.
  • Acknowledged the continuation of valid existing rights and uses, such as utility rights-of-way and water infrastructure.
  • Directed that the administration of these activities continue, but in a manner consistent with the intent of the designation.

This Monument presents an exceptional opportunity for the Forest Service to:

  • Demonstrate how resilient forest landscapes can co-exist side-by-side with major infrastructure.
  • Cultivate connections between a diverse urban population and the outdoors.
  • Use collaboration and partnerships to improve access, conservation education, and visitor services. 
  • Demonstrate that conservation of public lands is a great investment for the people and communities of Southern California.


image of prehistoric rock art

Prehistoric Rock art has been discovered in the San Gabriel Mountains. One of many historical artifacts that led to the monument's designation.

Designation as a national monument recognizes the area’s important geological, ecological, historic, scientific and recreational resources. There are more than 600 archaeological sites within the monument, including several rock-art and cupules features, the concentration of which is unique to southern California. Notably, two Native American rock art sites are listed on the National Register of Historic Places. Today, a number of tribes still use many of these sites to maintain their cultural and spiritual traditions.

The monument area also has a strong scientific history. Mount Wilson Observatory an internationally renowned astronomical research facility, used by notable scientists such as Edwin Hubble and Albert Einstein. Additionally, the San Dimas Experimental Forest, which was established in 1933 to study forest hydrology and ecology, is the only experimental forest in southern California. 

painted image of mt. wilson

Mt. Wilson, located above Sierra Madre, CA is of historical and scientific significance. The observatory contains two historically important telescopes: the 100-inch (2.5 m) Hooker telescope, which was the largest aperture telescope in the world from its completion in 1917 to 1949, and the 60-inch telescope which was the largest operational telescope in the world when it was completed in 1908 (Mt. Wilson Observatory).

The rivers of the San Gabriel Mountains National Monument not only provide drinking water to Los Angeles County, but are also areas of high ecological significance, supporting rare populations of native fish, animals, and plants. The monument area also includes four designated wilderness areas, as well as national recreation and scenic trails.