How South Dakota Measures Trail Width

A 64-inch side-by-side can look only a little wider than a 62-inch trail limit, but those inches can determine whether a route is open to your machine. Measuring the wrong part of the vehicle—or assuming every South Dakota trail uses the same rule—can spoil a ride before it starts. This guide explains how to measure, read width restrictions, and check routes before unloading.

What a trail width limit means in South Dakota

A limit describes the machine allowed on a route

A trail-width restriction is about the width of the vehicle you take onto the route, not simply how wide the trail looks from the staging area. A dirt road may seem roomy at its entrance and narrow quickly between trees, rocks, banks, or other obstacles. The posted or mapped limit helps distinguish which machines are permitted on that route.

In the Black Hills, riders commonly encounter a 62-inch width category. That number does not mean every route is suitable for every machine under 62 inches, or that every route wider than 62 inches is open to all vehicles. A route’s width designation is one part of its access rules; seasonal closures, vehicle type, and other restrictions can apply too.

The important distinction is that South Dakota does not have one universal width rule for every trail, road, and riding area. Many routes in the Black Hills are managed as part of the Black Hills National Forest’s motorized trail system, while other riding areas may have different site-specific rules. Always confirm the rules for the particular land and route you plan to use.

The route category is not a promise of physical clearance

A machine that meets a posted width limit is not guaranteed to pass comfortably through every spot. Trail surfaces change. A narrow section may be bordered by brush, a rock ledge, a cut bank, or a steep slope. A vehicle can be allowed on a trail and still require careful driving through its tightest sections.

Width also tells you nothing by itself about trail difficulty. A narrow route can be relatively smooth, while a wider trail can include loose rock, sharp turns, or steep climbs. For a fuller picture, combine the width designation with route notes and difficulty information, such as [South Dakota Trail Difficulty Ratings](South Dakota Trail Difficulty Ratings).

It helps to think of the width category as an access boundary, not a comfort rating. If you are close to the limit, or your machine has accessories that stick out, look for more detail before committing. The same caution applies when riding a machine that is within the limit on paper but difficult to maneuver in tight terrain.

How to measure an ATV or UTV for a trail

Measure across the outside edges of the tires

For trail-width planning, measure from the outer edge of one tire to the outer edge of the tire on the opposite side. This is the practical outside-to-outside tire measurement riders use when comparing a machine with a trail-width category. Do not measure between the tires, across the wheel hubs, or from the center of one tire to the center of the other. Those measurements will understate the machine’s overall width.

Park the machine on level ground with the tires pointed straight ahead. Use a tape measure across the widest tire-to-tire span, keeping it level rather than angled. Measure the front and rear axle areas if the tires or wheels differ in width, and use the larger result for conservative planning.

For a quick example, suppose the outside edges of your front tires measure 60 inches apart, while the rear tires measure 61 inches. Treat the machine as 61 inches wide for that comparison, not 60. If you are uncertain about the trail’s measurement convention or the machine is near the posted limit, contact the land manager before riding.

Check what extends beyond the tires

The tire measurement is a useful starting point, but it does not account for every accessory or modification. A side-by-side may have mirrors, wheel spacers, fender flares, nerf bars, a plow mount, or other equipment that projects beyond the tires. An ATV may have widened suspension, aftermarket wheels, or racks that change its practical clearance.

Measure or inspect the vehicle at its widest points, especially if something extends noticeably beyond the tires. Even where the trail category is based on tire-to-tire width, an accessory that sticks out can catch on brush or a rock wall. It can also make a tight turn more difficult than the published machine width suggests.

Keep both measurements in mind: the relevant tire-to-tire width for comparing with the route category, and the full practical width of the vehicle with its accessories. When a machine is near the limit, use the more cautious interpretation and confirm the applicable rule rather than assuming an extra inch will not matter.

Don’t confuse width with wheelbase or tire size

A vehicle’s width is not its wheelbase. Wheelbase measures the distance between the front and rear axles; it affects how a machine handles a crest or sharp dip, but it does not tell you whether it fits a width class. Tire diameter and tire tread width are separate measurements as well.

Manufacturer specifications can be useful, but check what dimension they describe. A listed vehicle width may refer to the overall body, tire edges, or another measurement point. If the specification does not make the measurement clear, measure the machine yourself and compare it with the route information.

This small bit of preparation can prevent a frustrating mismatch at the trailhead. Riders sometimes focus on engine size, seats, or cargo capacity when choosing a rental or planning a trip, then discover that a wide machine is restricted from a route they expected to ride. For route planning, check the width before booking or loading the trailer.

How to read width limits on maps and signs

Confirm the route, not just the general riding area

A map showing an open motorized area does not automatically mean every trail within it is open to every vehicle width. Restrictions can differ from one segment to another. A route may be open to machines under a certain width, while a nearby road allows wider vehicles. At intersections, it is possible to turn from a wider route onto a narrower one without realizing the category has changed.

Use the applicable travel map and look for width restrictions along the specific route you intend to ride. The [South Dakota Trail Maps and MVUMs](South Dakota Trail Maps and MVUMs) topic is a helpful starting point for understanding why motorized maps matter. OnX Offroad can also help riders view routes and plan a ride, but treat any app as a planning aid rather than a substitute for official maps, signs, or land-manager updates.

Before departing, identify the route’s name or number, note the width designation, and check every planned connection. This matters especially on longer rides where you may cross several trail segments. A route that begins with a broad, comfortable surface may eventually connect to a narrower trail with a different restriction.

Read signs at the trailhead and at route changes

Trailhead signs are useful, but they may not be the only place a restriction appears. Watch for signs at junctions, gates, and points where a route changes designation. If a sign at the trailhead seems inconsistent with the map, stop and resolve the difference before riding farther.

Do not assume a restriction disappears because the trail widens briefly. Width categories apply to the designated route, not just its narrowest-looking spot. Likewise, a broad entrance does not authorize a wider machine to continue onto a route that is restricted farther in.

If a sign is missing, damaged, or hard to interpret, avoid guessing. Use a current map, contact the relevant ranger district or site manager, and consider choosing a route with a clear designation. A few minutes spent checking can be far easier than turning a large machine around on a narrow, uneven trail.

Use apps as a supplement, not the final authority

Digital maps make it easier to plan a route, compare trail connections, and keep track of where you are. OnX Offroad can be useful for organizing a ride and reviewing route options before you reach the trailhead. It is still wise to cross-check the relevant official motor vehicle use map and follow the signs on the ground.

Map layers and route information can differ in how much detail they show. A digital line may help you see where a trail runs without displaying every width restriction, closure, or seasonal limitation in a way that is obvious at a glance. Save or carry the official map information you need, especially if you expect patchy cell coverage.

Before riding, compare your intended route across your sources. If an app appears to show access but a posted sign indicates a restriction, do not treat the app as permission to continue. The official designation and current on-the-ground controls should guide your decision.

Choosing a route that fits your machine

Compare common machine widths carefully

ATVs are often narrower than side-by-sides, but model names and appearance are not reliable ways to determine width. Two UTVs with similar seating capacity can have different dimensions, and tires or suspension changes can alter the span. Measure your particular machine rather than relying on a friend’s machine or a showroom impression.

What to check	Why it matters	Practical step
Outside tire-to-outside tire width	Helps compare the vehicle with a trail-width category	Measure across the widest axle on level ground
Accessories and modifications	Can affect practical clearance around obstacles	Check mirrors, spacers, flares, racks, and mounts
Route-specific limit	Different segments may have different access rules	Verify each planned trail on the official map
Current signs and closures	Conditions or restrictions may change	Read signs at the trailhead and junctions
Machine handling	A legal width does not guarantee an easy ride	Consider terrain, turning space, and your experience

If your machine is near a width threshold, build in a margin rather than planning around a barely fitting number. A small measurement error, changed tires, or an accessory can be enough to make a route a poor choice. When in doubt, select a route whose designation clearly accommodates your vehicle and confirm it with the land manager.

For a broader look at route options, [South Dakota Trails Under 62 Inches](South Dakota Trails Under 62 Inches) and [South Dakota Trails for a Wide Machine](South Dakota Trails for a Wide Machine) are relevant planning topics. Use them as a prompt to investigate specific routes, not as a replacement for checking the current designation of the trail you intend to ride.

Plan for the whole ride, including return routes

It is easy to check the outbound route and forget that the return trip may use different connections. A loop could include several width categories, and a shortcut on the map might put a wider machine onto a restricted segment. Review the complete route from staging area to destination and back, including any alternate exits.

Think through likely changes in the day. You may need to turn around because of weather, a closure, mechanical trouble, or a route that is more difficult than expected. If every return option depends on a narrow trail your machine cannot use, your plan is fragile. Choose a route with a suitable way back or identify a safe, permitted alternative in advance.

A planning app such as onX Offroad can help you visualize those connections, but use it alongside the official travel map and local signs. Also check [South Dakota Trail Conditions Before You Ride](South Dakota Trail Conditions Before You Ride) before heading out, since an otherwise suitable route can be affected by temporary conditions or closures.

Don’t ride around a restriction

If your vehicle is too wide for a route, do not try to bypass the restriction by driving along the shoulder, cutting through vegetation, or using an unmarked path. Going around a sign can damage the land and may put you somewhere that is not an authorized motorized route. It can also create a safety problem if the detour crosses an unstable slope or an unseen obstacle.

A restriction is not a challenge to test at the narrowest point. If you reach a junction and realize the route is not suitable for your machine, turn back where it is safe and legal to do so. If that is not practical, stop and seek guidance rather than pushing forward or improvising an off-route escape.

Rules beyond width can apply too. For example, [South Dakota Rules for a Machine Over 62 Inches](South Dakota Rules for a Machine Over 62 Inches) and [South Dakota Rules for Riding Off a Route](South Dakota Rules for Riding Off a Route) address related questions riders may need to consider. Check the specific area’s requirements before assuming that a different road, trail, or open space is available as an alternative.

Common width-measurement mistakes to avoid

Relying only on a brochure or online listing

A product listing can provide a useful starting point, but the number may not match how you need to compare the machine with a route. Specifications can refer to body width, overall width, or another point on the vehicle. If the machine has been modified, the factory measurement may no longer describe it accurately.

Before a trip, verify the actual vehicle you will ride. This is especially important for rental machines, borrowed vehicles, and used ATVs or UTVs. Ask the rental provider or owner for the machine’s width and measurement method, then confirm the applicable trail category yourself. Don’t assume a model name means all versions have identical dimensions.

Checking only the entrance sign

A sign at the staging area can tell you a lot, but it may not describe every route segment in a network. Riders who set out without checking junctions can unknowingly enter a route with a different limit. Make a plan that includes the route number or name and the restriction for each segment.

When a route splits, pause long enough to confirm which branch you are taking. A paper map, official digital map, and clear notes on your planned loop can reduce confusion. If signs and maps appear to conflict, take the conservative option and ask the land manager before continuing.

Treating the width limit as a skill or difficulty rating

Width classifications help determine access; they do not tell you whether the route suits your experience, passengers, or machine setup. A narrow trail may involve steep grades, loose surfaces, or tight turns. A wide route can still be challenging because of rocks, ruts, weather, or visibility.

Match the route to the whole group. Consider the least experienced rider, passenger comfort, machine handling, and the ability to turn around safely. If you are bringing children or riding in unfamiliar terrain, a route that is both clearly permitted and manageable is a better choice than stretching the width limit just to reach a particular destination.

A practical pre-ride width checklist

Before you load up, work through these steps:

1. Measure your machine across the outside edges of its tires, checking both axles if needed.
2. Look for accessories or modifications that make the vehicle wider or harder to maneuver.
3. Identify the exact trails and connecting roads you plan to use.
4. Check the current official map for each segment’s width designation and other restrictions.
5. Compare that information with posted signs at the trailhead and junctions.
6. Review current trail conditions and closures before leaving.
7. Plan a return route that does not depend on a restricted trail.
8. If the machine is close to the limit or the rule is unclear, ask the land manager before riding.

Taking those steps may feel fussy when everyone is eager to get moving, but it can save a ride from becoming a stressful turnaround. A clear measurement, a route-by-route map check, and attention to signs are the simplest ways to choose a South Dakota trail that fits both your machine and your plans.

Disclaimer

This article is for general informational purposes only and does not constitute professional advice. Laws, prices and regulations vary by location and change over time. Consult a qualified professional for guidance on your specific situation.