National Park Service Logo
PEPC Planning, Environment & Public Comment
PEPC Home Documents by Park Policy/Links Park Planning Search Documents

Ackerson Meadow Fence Installation

Yosemite National Park » Ackerson Meadow Fence Installation » Document List

This project will install boundary fencing to protect the natural resources and habitats of the new 415-acre Ackerson Meadow addition from cattle grazing on adjacent United States Forest Service (USFS) lands. The project will:
• Procure and install up to approximately 1.5 miles (7,125 LF) of new 3-strand wildlife-friendly barbed wire fence.
• Inspect and repair approximately 1.5 miles (7,650 LF) of existing fence at Ackerson Meadow and up to 6 miles (31,680 LF) of existing fence north and south of Ackerson Meadow
• Remove hazard trees that threaten worker safety.
• Provide survey and staking of boundaries and fence lines.

To protect wildlife, the park would use a combination of two strands of smooth wire and one strand of barbed wire, for a total of three strands that would be attached to standard 6-foot metal T-posts. T-posts are set 16-inches deep and 10 feet apart. Post spacing may extend up to 20 feet apart to avoid sensitive archeological sites or other features. The lowest wire will be smooth and a minimum of 18 inches above ground level. The middle wire will be barbed and approximately 12 inches above the bottom wire. The top wire will be smooth in order to minimize risk to birds and other wildlife and will be installed 40-42 inches above ground level. Deviations up to 30 feet from property boundaries may be made in discussion with USFS to avoid archeological sites and sensitive natural resources. Visibility markers will be added to the top and bottom wire (smooth wire is less visible than barbed wire) to provide visibility to wildlife. Small wire gates will be added in strategic locations to allow cows that breach the fence to be removed without having to cut the fence. Turn-style gates may be added to prevent entry by cattle but allow public access through the fence in strategic locations.

Fence installation will be conducted by a contractor and licensed surveyor to locate all property corners and set fence posts in accordance with property boundaries. Where fence lines deviate from property boundaries, boundary markers will be installed on trees or carsonite posts (0.2 inches x 4 inches x 70 inches, driven 16 inches into ground). Materials, including T-posts, wire, and pre-fabricated bracing, will be transported along the fence alignment via off-road vehicle where conditions allow.

Shrubs and small trees less than 4 inches in diameter may be pruned or removed if they interfere with fence installation. Dead trees, of all sizes, that pose safety hazards to fence installation crews may be removed by cutting with chainsaws. Downed wood across fences to be repaired and across dirt access roads may be removed by cutting with chainsaws. Fence posts (T-posts) may be placed by hand or, if accessible, by vehicle mounted equipment. Fence wire may be attached to trees, in place of posts, if trees are on the surveyed alignment and would otherwise need to be removed; pieces of wood would be placed between the wire and the trunk of the tree to prevent girdling. Where existing wooden post fencing is no longer needed, the fence wire will be cut and wrapped around existing wood posts, however, T-posts, documented as less than 50 years old by the park archeologist will be removed. Modern T-post fencing replaced in 2014 after the Rim Fire will be completely removed where it is no longer needed.