This is part of a game called Caballus

Marathon

The Marathon is, in essence, a "cross country" course competed in harness. The horses are driven over a preset, cross country course, over varied terrian, with hazards and obstacles that need to be driven through rather than jumped. There are two types of Marathons, the pleasure marathon, and the Combined Driving marathon. Pleasure Marathons are independent events that are hosted at Carriage Pleasure shows, while the Combined Driving marathon is a phase of the Combined Driving Event.
Pleasure Marathons
There are three types of Pleasure Marathons, Pleasure Marathon Turnout, Pleasure Marathon -- Timed, and Pleasure Marathon -- Pace. It is probably best accurate to compare Pleasure Marathons to Hunter Trials and Hunter Paces rather than Cross Country. The pace and obstacles are easier, and far less stress is put on the horse.
Pleasure Marathon Turnout
The Pleasure Marathon Turnout gives the competitors a chance to turnout in their finest while competing in a pleasure marathon. At the beginning of the class drivers will be observed by the judge in a ring at a walk, slow trot, working trot and strong trot. Horses will be asked to halt and rein back.
Following this preliminary judging, the each class will be sent out on course (order of go and timing to be at management’s discretion). Drivers are encouraged to carry a groom/navigator who may assist in pointing out the route, but may not handle the reins, whip, or brake. The designated course may be of any length with no time limit. Care should be taken in designing the course to consider the antique vehicle and smooth tracks should be utilized when possible. The recommended gait is a trot, but the competitor may walk at his pleasure. Cantering is not permitted at any point of this marathon. Rules of the road must be obeyed, unless a uniformed police officer directs otherwise. Fitness may be checked at the conclusion of the drive by a veterinarian or, in his absence, by the judge and may be considered accordingly.
Once the course is over, the entries may once again be asked into the ring to be observed by the judge. The class is judged on 50% on overall impression and 50% on way of going. Great importance is on the suitability of each entry as a pleasure to drive. The horse's manners, way of going, condition, appropriateness, and grooming; as well as the condition, appropriateness, and cleanliness of the harness and vehicle; and the driving skills, posture, appropriateness, and neatness of attire of the driver are all considered towards overall impression.
The Pleasure Marathon Turnout is an easy Marathon for people who would like to enjoy cross country driving, while showing off at their best and most elegant.
Pleasure Marathon -- Timed
The timed pleasure marathon takes place over a course of a suggested length of 3 to 6 miles in length, though any length is permitted. A rest period is recommended to be included for any course at or over 6 miles. The timed pleasure marathon is composed of two sections, a trot section, and a walk section. The walk section is from 250 to 500 yards. The obstacles on the course must be driven correctly or a penalty will occur. Cantering is not permitted. A vet will inspect horses at the end of the course, horses that do not pass the vet inspection are given 10 penalty points.
Like a Combined Driving marathon, the timed marathon has both a minimum time and a time allowed, so the competitor must control their pace and neither go too fast nor too slow. In cases of a tie in score, the judge determines the winner by decided which horse is more suitable as a pleasure drive.
A timed pleasure marathon is a good marathon for teams that hope to start Combined Driving, and wishes to gain marathon experience before starting out.
Pleasure Marathon -- Pace
The best mounted comparison to a Pleasure Marathon -- Pace, is a Hunter Pace. An optimum time is determined beforehand, and the entries trying to be closest to that ideal time. There are two sections, a walk section and a mandatory trot section, with breaks from the required gait to be penalized. There are no hazards and few obstacles.
The course can be from 3 to 6 miles, with the option of creating a mandatory walk section near the midpoint of the course. The last kilometer must be driven at the trot, and at no point during this section may the entry circle or drive serpentines in order to try and gain more time on course. Breaks from the trot during this section will be penalized.
The pace is a good marathon for drivers willing to test their skill and ability, as well as knowledge of their horse(s) and their horse(s) pace and gait.
Combined Driving Marathons
The object of the CDE's Marathon phase is to test the fitness, stamina
and training of the horses/ponies and the driving skill, judgment of pace
and general horsemanship of the Competitor.
The course is divided into sections, with there to be three to five sections, depending on the level of the event. Each section has a set pace and both a minimum time and a time allowed to finish the section. The five sections, A, B, C, D, and E, are either free, allowing the entry to chose their own pace, or restricted to walk or trot. Section A is always a free gait section, B is always restricted to the walk, C is restricted to the trot, D to the walk, and E, which is the obstacle section of the course, is restricted to the trot for Training and Preliminary levels, but is free gait for Intermediate or Advanced.
Training and Preliminary have three sections, A, D, and E. Intermediate and Advanced may have either three sections (A, D, E) or all five sections. There is a compulsory rest of at least 10 minutes after section B and section D. Distances vary from 4 kilometers to 22 kilometers, depending on the level of the event. The number of obstacles in section E varies from 5 to 8 depending on the level. Number of gates the entry must go through within a given obstacle (the more gates, the greater the length and complexity of the obstacle) increase with the level. Some obstacles ask the horse to negotiate water crossings, tight twists through trees or even the visual problems created by lines and lines of fences or pens with narrow openings. Drivers must find the fastest route through each obstacle since their score is based on how long they spend in the "obstacle zone". There is a five minute time limit for each obstacle.