Selection and Installation Considerations
- Deschutes Trail Cattle Guard
- Caribou Trail Cattle Guard
- Deerlodge Trail Cattle Guard
- Challis Trail Cattle Guard
Think about links between safety and trail-user psychology when choosing a design. Traveling fast is part of the thrill for many off-highway vehicle (OHV) users. But in the back of their minds most users also want to travel safely. Most users will slow down if they perceive danger or a hazard.
This is where your selection of cattle guards and their placement can affect the behavior of trail users. The Forest Service does not want to encourage reckless behavior.
Keeping the cattle guard narrow is probably the best way to convince users not to speed. If they think it will be a challenge to get across the cattle guard without mashing their fingers or scraping their machines, they will usually slow down. For ATV users especially, a cattle guard only slightly wider than their machine means they will voluntarily slow down to avoid hitting the sides. A narrow cattle guard blocks vehicles wider than those allowed on the trail.
So how wide is wide enough? This is a tricky question, because ATV's seem to be getting wider each year. In some cases the width of a large ATV differs little from a small four-wheel-drive vehicle (Figure 1). The width of the cattle guards described in this report range from 4 feet (1.2 m) to 5 feet (1.5 m). Cattle guard widths of 52 to 60 inches (1.3 to 1.5 m) will allow most new ATV's to cross-just barely. Build them wider and you risk indiscriminate use by four-wheel-drive vehicles, which may not be allowed in your management plans. They are also too heavy to be supported by the cattle guards. Four-wheel drives will damage cattle guards, and their owners may claim damages if their vehicles are harmed (Figure 2).
Angling the wings of the cattle guard from top to bottom allows the top to be wider. This is often desirable to give riders, especially on motorbikes, a little extra margin for error to avoid catching their handlebars on the fenceposts.
Where your cattle guard will have little psychological effect on speed (in wide-open country, for instance), consider using the flat Deschutes Cattle Guard instead of elevated designs to avoid sudden loss of control caused by a change in elevation.
Psycowlogy comes next. Will you be able to fool the cows into thinking your trail cattle guard is an impenetrable barrier to the greener grass and freedom on the other side? Probably.
The four cattle guards featured here actually work. Even when bunched up, cattle avoided these cattle guards. A trail cattle guard that meets these specifications should work:
Length from 5.6 feet (1.7 m) for the Deerlodge Trail Cattle Guard to 13 feet (4 m) for the Caribou Trail Cattle Guard
Suitable wings or side barriers (Figure 3)
Spacing of about 4 inches (100 mm) between the tread rails.
If the cattle guard is too short, lacks side guards or wings, or has incorrect spacing between the tread rails, cattle may be tempted to try to jump it or walk through it. We heard of one instance of a cow that had to be destroyed after it got its leg caught in another type of trail cattle guard.
In many cases, a wire fence gate is needed near the trail cattle guard for horse riders and to allow cattle to be moved between pastures.
A few practical considerations in the design are:
Steel or wood-Steel offers long life and strength. Wood is easy to work with and might be preferred for esthetic reasons. Our examples include the all-wood Challis design, the all-steel Caribou design, and two steel designs (Deerlodge and Deschutes) that have steel, but have wood sills or bases.
Transportation-The Deschutes and Challis designs can be assembled onsite or in the shop. The Caribou and Deerlodge Cattle Guards are fabricated in the shop. All designs can be hauled to the trail site in pickup trucks or on trailers pulled by ATV's, but there are substantial size and weight differences.
Installation-Cattle Guards that lie flat on the ground (Deschutes) require excavation and periodic cleaning. Elevated designs like the Deerlodge and Caribou can be placed without excavation (except for support sills for the Deerlodge design). The all-wood Challis Trail Cattle Guard also needs periodic cleaning. Volunteers or force-account crews can install any of these cattle guards without heavy equipment.
Cost-Cost is an important factor. We have not verified costs down to the dollar, because they vary considerably due to labor for installation, materials (new or used), and the fabrication rates charged by local shops. None of the four designs is especially complicated to construct or install. Materials for the Deschutes Trail Cattle guard cost about $550. The Deerlodge Cattle Guard cost $235 the last time a shop fabricated some (sill timbers would also be needed). Materials for the Caribou design run about $150 with new materials-less if it is made with used steel fenceposts. We do not have cost information for the Challis design, but using treated lumber is worth the expense.
After putting a lot of thought into a design, Dick Dufourd began installing these cattle guards on the East Fort Rock OHV trail system, Deschutes National Forest, in 1986. Since then, many more have been installed at BLM and Forest Service sites in central Oregon and throughout the Pacific Northwest. Both the Forest Service and BLM believe that the cattle guards have performed beyond expectations, at reasonable cost, and with minimal maintenance.
The Deschutes Trail Cattle Guard looks and works like a traditional road cattle guard. It provides a flat running surface (Figure 4). The design is a combination of a treated timber base and a steel deck made with an angle-iron frame and tread rails of square tubing. It is 5 feet (1.5 m) wide and 8 feet (2.4 m) long. The base is a wooden box constructed of 2- by 12-inch (50- by 205-mm) treated lumber. Lag screws attach the deck to the base. The wings are made of treated 2 by 4's.
Complete plans for the Deschutes Trail Cattle Guard are in Appendix A. All the materials for two cattle guards weigh about 600 pounds (270 kg) and can easily fit into the bed of a pickup truck. Although the cattle guard is designed to be assembled onsite, if the deck can be transported to the site in one piece, all of the tread rails could be welded to the angle iron frame except for the last three on each end, which would be bolted. Welding reduces fabrication time, and the bolted tread rails provide cleanouts.
Maintenance is infrequent and easy. You simply unbolt some of the rails and scoop out dirt that has accumulated beneath the cattle guard. The approaches tend to get beat out with heavy use, especially in soft soils. These need to be raked smooth. In some situations, it may be desirable to harden the approaches with a soil stabilizer, geoweb, or some other trail-hardening technique to keep the soil in place.
The Caribou Trail Cattle Guard was designed by Carl Stoddard, Mark Booth, and John Newcom from the Montpelier Ranger District, Caribou National Forest, Idaho. This all-steel cattle guard features economical recycled steel fenceposts and is fabricated in the District shop (Figure 5). It has been used since 1995. Cattle were bunched and held against this trail cattle guard, and were also crowded through gates right next to them, but there wasn't a single attempt to breech the ramp.
Installed, the cattle guards are 13 feet (4 m) long. They are constructed in two pieces and bolted together onsite. They can be carried in a pickup truck or on an ATV trailer.
Perhaps the major cost advantage for this design is the fact that installation takes less than 1 hour and can be accomplished easily by two people. There is no need to dig a pit or set brace posts. You simply cut any wire in the fence that is higher than 22 inches (560 mm) above the ground, set the two halves of the cattle guard in place on either side of the fence, bolt them together, and tie the fence back into the wings of the cattle guard. The ground need only be relatively flat and not too boggy.
Steel angle iron, 2 by 2 inches (50 by 50 mm), could be substituted for the steel fenceposts used here as tread rails. They would be welded at both ends to the box-tubing "stringers" with the point of the angle facing up.
This cattle guard is built with galvanized chain link fence material underneath the tread rails and over the X-shaped flat-iron support bars (Figure 6). The chain-link fence helps prevent users from slipping a foot or wheel between the tread rails. Cattle still avoided the cattle guard even with the chain-link fencing in place.
The original design was 44 inches (1.1 m) wide, but in the plans in Appendix B we widened it to 52 inches (1.3 m) to accommodate wider ATV's. The District has constructed them 36 inches (.9 m) wide for trails where ATV's are not permitted.
Eric Tolf, from the Jefferson Ranger District, Beaverhead-Deerlodge National Forest, Montana, and the late Darrow Hippert, McGrew Machine and Fabricating in Whitehall, Montana, designed the Deerlodge Trail Cattle Guard (Figure 7). It is an elevated design and is shorter than the Caribou or Deschutes Trail Cattle Guards.
The original design called for 2- by 1-inch (50- by 25-mm) steel channel for the tread rails. The plans included in Appendix C show an optional design using 2- by 2-inch (50- by 50-mm) steel angle instead, which should cost less.
The cattle guard needs to be bolted to at least 2- by 6-inch (50- by 300-mm) treated timbers at both ends (the plans show welded tabs for bolting). These timbers are buried. Larger timbers could be used to raise the entire cattle guard, with the approaches built up to provide a smooth transition.
For a more substantial side barrier, you might consider constructing two short H-brace fences running in the same direction as the cattle guard.
Howard Rosenkrance documented this design some years ago on the Lost River Ranger District of the Challis National Forest, Idaho (Figure 8). According to District staff, this all-wood design is still being used and serves its intended purpose.
Plans are included in Appendix D. If the cattle guard is set on railroad ties at two ends only, minimal excavation would be needed to level the ties. Approaches could be built up for a transition to the cattle guard. The lumber can be precut and assembled onsite. Buying treated lumber and applying additional treatment to any cut surfaces is a good investment, because it will help keep the structure from rotting.
The specified tread rail width is 48 inches (1.2 m). However, they can be widened to handle the larger ATV's-or made narrower, for that matter. The wings made out of 2 by 4's are tied into the existing fence.
All of these designs can be fabricated by District crews or at local fabricating shops. You may also want to consider the sources below for a couple of the designs. This listing does not constitute an official endorsement by the Forest Service.
Deerlodge Trail Cattle Guard
McGrew Machine and Fabricating, Inc.
5 South Division Street
Whitehall, MT 59759
Phone: (406) 287-3916
Caribou Trail Cattle Guard
The Montpelier Ranger District may be willing to fabricate these at cost for other Forest Service units. For more information, contact John Newcom or Mark Booth at:
USDA Forest Service
Montpelier Ranger District
322 North 4th Street
Montpelier, ID 83254
Phone: (208) 847-0375