The Definitive Guide to Marking a Trail Race
LAST UPDATED: 11 September 2024

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If you're a trail race organizer, marking your course will be one of the most important and time-consuming parts of your job.
If you're new to this - or even if you're not and you're only after a few pointers - we've put together a crash course with everything you'll need to mark your trail course, from planning your purchases to making the most of your time out on the course.
And it all starts with...
The rules
Before the hows and the whats and the what-not's, it's useful to take in some ground rules.
- Be explicit. When it comes to course marking, there is no such thing as "obvious". Something that may be obvious to you, will not be obvious to a first-timer on the course. Furthermore, something that is obvious to a 12min/mi runner may not be obvious to a 7min/mi runner or someone who has been sleepless for 24+ hours. So if in doubt, mark it out.
- Think of the environment. Marking should be a balancing act between providing as much information as is necessary to ensure a safe navigation and having as little of an impact on the environment as possible. If you can, try re-using and maintaining existing marks before adding new ones.
- Communicate. Before marking your course, make sure local authorities, residents, the police and all relevant agencies are fully on board with what you're planning to do. If your marking requires private access permission, get landlord consent before you begin.
- Be consistent. Come up with a set of trail marking conventions and stick to them throughout your course. If you are getting help from others, make sure the same rules are followed by everyone, down to the color, size and style of arrows, signs and waypoints.
- Keep it simple. Avoid using elaborate or over-explicit marks. Most of the times you'd want to either point direction with an arrow or affirm direction with a dot, square or other symbol. Do, however, make sure your marks stand out against the trail background and look clearly man-made.
Marking materials
Depending on the exact nature, budget and time of year of your race, there will be a range of materials you could use on your course. The following list includes some of the more common choices of marking materials.
Barrier tape
Usually hung from tree branches at eye level, barrier tape is an excellent choice for marking trails. It is lightweight, easy to put up and can be highly visible against vegetation even from a distance. The red-on-white garden variety is great and you can also get reflective versions (red-on-silver-coated) for marking night segments.

Lots of people use barrier tape to mark their course - and sometimes the same type of barrier tape as everyone else. So, if you want to avoid taking the blame for marks left behind by someone else, why not add a sticker at the back of your barrier tape with your event name and contact information? That way you can always be sure your race clean-up efforts are rewarded by the community and local authorities.
Hi-visibility tape
If reflective barrier tape is either not visible enough or inappropriate for certain trail segments (e.g. when vegetation is not available to hang tape from) you can go one better with hi-vis reflective tapes, like the 3M Grade 983 tape pictured above. These are a bit expensive, but a little can shine a very long way.

Spray paint
Spray paint is a versatile marking material, which needs to be used considerately in the outdoors as it leaves a permanent mark on the environment. Where possible biodegradable types of paint should be preferred, although chemical paints in general should be avoided in favor of organic alternatives (see below).
If you are going to use spray paint, go for reds and oranges that are highly visible and make sure to consult with other race organizers, mountaineering clubs and local community stakeholders in creating a marking scheme that will minimize the impact on the environment.
Spray chalk
For a less permanent alternative to spray paint, you can use spray chalk. Spray chalk is a washable, non-toxic, animal/vegetation-friendly powder spray that can be washed away and will naturally dissipate 10-20 days after application. Like starch paint (see below) it can be used on grass, asphalt and most hard surfaces, having the convenience of spray application without the side-effects of even the best biodegradable spray paints.
Flour/starch paint
Flour-based homemade paints are a good biodegradable, non-toxic alternative to chemical paints. You can easily put together these paints at home and can apply them with a brush or roller the same way you would apply regular paint, although carrying the paint with you to hard-to-get places won't be easy. The upside is any marks you apply will easily be washed away by rain. The downside is just the same.
Fixed signs
For those crucial junctures in your course where you want to make sure everyone knows where they're going, you can use ad hoc signs to indicate direction. These signs can be laminated cardboard or any other purpose-made sign. You can tie the signs on to trees (try to avoid stapling) or, where trees are not available, on poles that can be fixed on the ground.

Marking flags
Marking flags, sometimes used for surveys, make excellent ground markers in places where it's not possible to use barrier tape or paint. These flags come with tall 10''+ wire stakes and are both durable and light in carrying around. Do keep in mind, though, they may pose some danger to animals.

Other things you'll need
Nails or staples, a hammer, heavy duty twine and some duct tape can all come handy out on the course for fixing signs and, in some cases, barrier tape in place. Make them as lightweight as possible as you could end up carrying them for hours.
Planning & preparation
Before you start marking any trails, there are several things you can do to make the whole process more efficient:
Go over the course
Literally - spend as much time out on the course as you can, going over it in the direction of travel. Make notes of potential hazards and high-risk areas. Put yourself in your participants' shoes and ask yourself how someone could get lost or injured. Make notes of areas where marshals or bespoke signs may be required so you can plan your provisions and volunteer staffing accordingly.
Try marking materials out
This is particularly important for longer trail races where there may be a few days between putting down the first and last marks on the course. To test how well marks hold together with time, take a sample of your marking materials out on the course and put down a few test marks, then revisit those marks a few days later and observe how their quality degrades over time. Do this early enough so you can test different types and brands of materials before purchasing large batches.

Use placeholders
If, when going around the course, you think a particular mark may be necessary and want crews that will follow later to add a mark in the exact same spot, this is the time to put a placeholder down.
Time yourself
For long and varied courses, like in ultra races, it makes sense to have an idea of how long marking the course will take and how many people will be required.
Not all terrain is equally easy to mark, so break your course down to all the different types of terrain (rocky, dirt trails, road etc) and calculate how long it takes to mark 100m or 1km of each, so you can be sure you have enough time and people to mark the course in its entirety when the time comes.
Identify night segments
If your race includes nighttime sections, it is important to know exactly what those sections are. That way you can make provisions for suitable materials (reflective tape/paint), as well as human resources.
The way to figure out the night sections in your race is by figuring out two points along your course. The first point is the point where dusk will catch up with the slowest runner in your race. The second point is the point where dawn will catch up with the fastest runner in your race. Everything in between will have to be marked for night conditions, as at least one of your participants will be in that section during the night.
Execution
The way you lay marks on the course can make a big difference. You won't get all this right straight away, but with time and practice this should become second nature.
Aim for 1-2 visible marks at any point on the course
The textbook advice is that only one mark should be visible from any one point on the trail, in order to avoid confusion. We say it's ok to have more than one visible marks (but not too many), as long as additional marks are necessary in laying out direction and can easily be distinguished from the nearest mark.

Place marks on ground or at eye level
Most runners in a race will be looking out ahead and down for obstacles and the fastest among them will barely glimpse ahead or on the side for course marks. Keeping your tape at eye level and paint marks at eye or ground level makes sense.

Use affirmation marks
Besides the marks telling runners where to go, it's good practice to use marks to tell runners they're still on the course.
There are two kinds of these marks you should use. The first are marks that tell a runner they're on the course following a direction change - these can be as subtle as a dot of spray paint a few yards after a course junction.
The second are "still on the course" marks - these will reassure runners they're still on the right track when direction hasn't changed for some time.

Take pictures/notes
If you are putting together a race manual or following up with a pre-race briefing - and you should aim for both, if you can - it will help to include information about your marking scheme in both of them. Providing pictures of your course marks is the best way to give your participants a flavor of what to expect on race day.
Pre-race to-do's
You've got all the information from your long days marking your course, now it's time to share them with your participants - and your teams on the ground.
- Add information about your marking scheme (including pictures) on your race manual. If you are not providing runners with a race manual, write a blog post or article with that same information and mail it to your participants, post it on Facebook etc. Make sure to invite feedback - and action that feedback once you have it.
- Make some time to go over your marking during your pre-race briefing. Same rules on feedback apply here - answer participants' questions and, if comments point to last-minute changes, instruct teams on the ground to carry them out on or before race day.
- Issue aid stations and volunteer teams with spare marking materials , such as spray paint and barrier tape in case they need to repair damaged marks or beef up existing marking on the fly. If possible, get volunteers to inspect the more vulnerable segments of the course on race day or the evening before for the inevitable case of vandalism.
Race day to-do's
If you've invested the time to mark the course and plan for race day, chances are everything will go according to plan.
Nevertheless, be ready to take action even during the race if necessary (e.g. you notice that despite your best efforts participants report confusion to staff on the ground about particular marks on the course).
Post-race to-do's
Well done - the hard part's taken care of :)
Still, work doesn't quite end there for you. Here's the last couple of things you'd want to do to make sure everyone keeps coming back to the race for years to come.
- Take feedback. This is the time to ask runners what they thought of your marking and whether there are areas you could improve on. Usually, if you do this within a couple of days after the race, when your participants are at their most engaged, you will get some clear, constructive suggestions.
- Clear the course of marks and other materials. Depending on what you've agreed with local authorities and the types of marks you've used, you may have to go over the course and remove your marks, particularly things like barrier tape. You can put those back up next year.