Endurance rides have many variables. Some areas have high humidity, some low. Some trails are rocky, some sandy and some wet and muddy. There are ride days that are hot and sometimes cool or cold. But there is one thing that should not be a variable -- distance. The distance should be measured, known and advertised so riders know how far they have to go at all times. The distance should not be adjusted for difficult conditions. If you have ridden a trail that you feel is significantly off in measurement, you should contact your regional director who can then consult the ride manager on the issue.

There are lots of ways to measure the distance of a trail. If the trail is road or good two-track you can measure the distance with a vehicle like a pickup or a Jeep. Be careful that the odometer is calibrated. Many off-road vehicles, like my own Jeep, have changed tire size and need the odometer calibrated to correctly measure distance.

Bikes, ATVs and motorcycles

All-terrain vehicles (ATVs), motorcycles and mountain bikes are good for riding on trails if they are allowed. Many have odometers. Again some are good; some aren't -- so they need to be calibrated. Nick Warhol, another ride manager and regional director, uses a very accurate rally odometer on his dual-sport motorcycle.

Nick is a motorcycle racer -- and a fast one at that, he says. Nick thinks using a motorcycle is best because it can go anywhere it is allowed, even places where a quad or Jeep can't. And it's a lot faster, if you are a somewhat accomplished rider. Almost every area of the U.S. has motorcycle riders willing to help measure the distance of a trail if they are contacted, know where to go and have permission. Nick says one thing to remember when measuring a trail with a bike is to stay on the trail -- no U-turns, spin-outs, wheelies, etc.

The instrument Nick uses on his motorcycle is an ICO Racing Dual Sport model. It provides an accurate odometer with easy-to-adjust distance readout. This instrument automatically calibrates wheel size to match the bike used for route layout.

GPS measurement

A popular instrument for people to carry on trails these days is a GPS. They vary in accuracy and always seem to measure short by some percentage. These instruments were designed to get a point (set of coordinates) accurately but measure a straight line between points. So if points are not taken frequently they can be inaccurate. Northwest Regional Director Bob Morris says he has used a differentially corrected GPS for years and found it to be a very good measuring tool. The following are Bob's comments on using the GPS for trail measurement.

Trail measurements for endurance rides can be made using GPS systems and can be done in a reasonably accurate way. As in utilizing any measurement systemÑodometer, measuring wheel, or even measuring tapeÑcare must be taken to assure accuracy.

Initially, the GPS unit selected for the task must be of a standard that will produce the needed results. A survey-grade unit should be employed, not the regular consumer handheld GPS units sold in sporting goods stores. All federal and most state agencies employ this type of unit on a regular basis. These agencies are very often willing to assist in measuring trails.

A systematic approach to the actual measuring is needed to save time and effort. Knowing the actual route to be measured will save much time and confusion. The position acquisition of the GPS unit is normally set at five seconds. A position is taken every five seconds, and under most conditions this is very satisfactory.

It is often beneficial to measure the trail in short sections, especially varying sections of the trail to be used between vet checks. It is better to break up each leg into two or more sections. This makes it easier to modify the route without extensive re-measuring.

After obtaining the field measurements, differential reduction of the data should be done and then it is best to plot the route on paper. Most GPS systems have accompanying software for this purpose. Looking at the plot of the route, it is easy to see any portions of the route that may have been missed by lack of signal. These will be extensive sections of straight lines with no data acquisition points in them. If extensive, these sections can be re-measured to complete the survey. When all sections of the trail have been measured correctly, you will have your trail length as well as an accurately plotted map for the competitors to use.

There are additional benefits that are found in the use of accurate GPS units and one of them is the land management agencies can then incorporate the information in their trails management system. It also aids immensely in obtaining permits from the likes of the Bureau of Land Management and the U.S. Forest Service.

This information is somewhat technical but many who work with government agencies are asked to take the proper training and do trails this way to get the information the agency desires.

Surveyor's wheel

Of course, another accurate way to measure a trail is with a surveyor's wheel. Not many ride managers have volunteers that will walk all the trails and I have yet to see an accurate surveyor's wheel that you can tow behind your horse.

Accuracy is the key

The important thing is to find a way to accurately measure the distance of your trail. Make 50 miles really 50 miles and 100 really 100. Then let the riders know the mileage at various points so they know the distance to the next stop whether it is a vet check, finish or just a way point. Make sure your various measuring devices are calibrated for the terrain they are measuring. Don't check a GPS straight down a road and then say that it is the right calibration for a rough mountain trail. Don't use a modified off-road vehicle that has not been calibrated.

Many of the AERC directors are also ride managers or have been ride managers. They are willing to help so don't be shy. Contact a regional director and he or she will see what to do to help you get your trail measured accurately.