Intermittent Closure along Marshall Canyon Trail Due to GSOB Mitigation Efforts
Date: Weekdays from April 2026 - June 2026
Location: Northern Segment of Marshall Canyon Trail
Closure Start Date: Week of 4/20/2026
Visitors are advised that a portion of Marshall Canyon Trail is temporarily closed as part of ongoing mitigation efforts targeting the Goldspotted Oak Borer (GSOB), an invasive pest that poses a significant threat to native oak trees. There will be intermittent closures along a segment of Marshall Canyon due to oak tree pest management and tree work activity. These temporary closures will occur on weekdays from April 2026 to June 2026.
Please see map below that highlights the impacted segment.
Why the Closure is Necessary
The Goldspotted Oak Borer (GSOB), Agrilus auroguttatus, has been detected in Marshall Canyon along the multi-use trail and surrounding canyon areas. This invasive pest lives beneath the bark of oak trees and is contributing to ongoing oak tree mortality across federal, state, private, and Tribal lands throughout parts of Southern California, including San Diego, Riverside, Orange, San Bernardino, Los Angeles, and Ventura counties.
Treatment of GSOB-infested trees will be conducted by Los Angeles County Fire Department Forestry Division/Invasive Pest Management Unit, the Agricultural Commissioner/Weights and Measures, and the Los Angeles County Department of Parks and Recreation.
To read more about the Goldspotted Oak Borer visit: gsob.org or if you suspect a Goldspotted Oak Borer infestation in your area, report it HERE.
Staying Informed
For Up-to-date information on trail closures: CLICK HERE
Social media channels: @trailslacounty, @lacountyparks
We appreciate your cooperation as we work together to protect our oak woodlands and ensure safe recreational access for the future.
