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Most forest management plans include scheduled timber harvesting. Harvesting includes felling trees and transporting logs on skid trails to a landing where products are sorted and loaded onto trucks for transportation to a mill. Skid trails are temporary travel-ways for logging equipment to transport felled trees or logs to a landing. They are not intended for off-road-vehicle use. Skid trails that require excavation need careful design and should follow BMPs for Forest Roads. Landings may be permanent or temporary features. If permanent, they may be used as parking areas or wildlife openings.
Planning
Limit the length and number of skid trails, and the number of landings and stream crossings to the minimum necessary to conduct the harvest.
For BMPs concerning skid trails and landings in wetlands see Wetlands.
Logging Equipment
The type and use of logging equipment should be appropriate for the operation to minimize site disturbance. This means using the correct equipment for each job.
Logging equipment should be operated during suitable ground moisture conditions in order to avoid excessive site damage. When avoidable, do not log in wet weather.
Harvesting
When harvesting near streams or lakes, follow BMPs Streamside Management Zones.
Whenever possible, winch logs from steep slopes if conventional skidding could cause erosion that affects water quality.
Avoid operating equipment where excessive soil compaction and rutting may cause erosion that affects water quality. The use of low ground pressure equipment may allow operations to continue.
Fill in ruts, apply seed and mulch, and install sediment-control structures and drainage structures on skid trails and landings where needed to prevent erosion and sedimentation into surface waters. See the Drainage Structures and the Soil Stabilization section of Forest Roads.
Inspect soil-stabilization practices during, and immediately after, harvest operations to insure they are successful and remain functional. Follow BMPs in the Road Maintenance section of Forest Roads.
Do not pile slash into drainage areas where runoff may wash slash into streams, lakes, or wetlands.
For winter harvesting, mark stream channels and existing culvert locations before snowfall.
Landings
Appropriately located landings are essential for a successful harvest operation. Landings are high use areas being the hub of the skidding trails and the terminus of a logging road. Special care must be taken to assure that the landing is adequate for its purpose and that construction and use of the landing is done with minimum disturbance to the area.
Locate landings outside streamside management zones.
Locate landings on firm well-drained soils with a slight slope, or on ground shaped to promote efficient drainage. Landings may need a crown shape to allow for drainage.
Use existing landings if possible. Close existing landings in streamside management zones unless construction of new landings will cause greater harm to water quality than using existing landings.
Locate residue piles (sawdust, chipping residue, etc.) away from drainages where residue may wash into streams, lakes or wetlands.
Retire and restore landings. The landing area should be cleaned, graded (and ripped if necessary), and sown to suitable, fast growing vegetation. Consideration should be given to plant species favoring wildlife. Plan to use this same landing for future harvest.
Skid Trails
Skid trails are used to move logs from the stump to the landing. This necessitates repeated trips over the same area and often over the same skid trail(s).
Skid trail restrictions in streamside management zones are described in Streamside Management Zones.
Where possible, keep skid trail grades less than 15%. Where steep grades are unavoidable, break the grade, install drainage structures, and use soil-stabilization practices (as described in Forest Roads) where needed to minimize runoff and erosion. Grades greater than 15% should not exceed 330 feet in length.
Use existing trails if they provide the best long-term access. Consider relocating existing trails if both access and environmental impact can be improved.
Consideration should be given to the number and layout of major skid trails. To the extent feasible, logs should be brought to a small number of major skid trails. Directional felling concentrates logs for a full "skid," minimizes trips and the extent of mineral soil exposure.
While skidding logs, the lead end of the log(s) should be elevated to minimize gouging of the skid trail.
Skid trail layout and design should be developed prior to the implementation of a harvest. Doing so improves the efficiency of the operation and reduces costs.
Stream Crossings for Skidding
For skidding across streams, use permanent crossings as described in General BMPs for Stream Crossings section of Forest Roads.
Pole fords may be used in small streams by placing poles (or small logs) side by side on the streambed (Figure 3-1). Pole fords should be removed immediately after use.
Frozen fords are used in small streams when ice is thick enough, or the streambed is frozen enough, to protect the streambed.
Install stream crossing structures at right angles to the stream channel.
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