Riders need to use GPS to find their way across the steppe as there are no visible markings of the trail. The GPS also helps organisers and supporters track riders' progress.
"The vastness there is incredible. I expect the mental challenge will be as big as the physical one. The landscape just goes on forever. I also know I am going to be in pain a lot."
Having talked to those who have done the Mongol Derby before hasn't put her off.
"I have been training since January, go to the gym four times a week, do pilates twice a week, ride horses every weekend and have a very pushy personal trainer."
She has been an endurance rider for a while, something that will be invaluable during this adventure. Endurance riding means travelling at speed and that is what will be the norm during the Mongol Derby, where each 40km leg is non-stop.
"No time to stop and admire the view, or take photos. These horses do not stop for anything."
Experience as a competitive trail rider will also help her during the derby, as she expects to have to ride at least 120km a day to finish within the given time frame. "You must finish the trail in 10 days and if you want to win you need to do it in 7.5 days."
There are medics and vets at all stations, who check up on horses and riders each time.
"At the start you are given a horse but at stations you can pick one yourself. That horse will be saddled for you and I hear you may need help to get into the saddle as the horses need to be held steady at that time."
There is a time limit on each day's riding too.
"You may not ride more than 13.5 hours. If you do you get penalties. If your horse's heart rate takes too long to calm down at a station, you are also penalised," said Trudi.
Most riders will spend the nights at the stations, but you can seek refuge with a local family.
The weight limit on gear permitted on the horses is a challenge in itself. "We are allowed only 5kg of luggage. That includes everything: food, sleeping bag, cold weather gear, wet weather gear, change of clothes."
She's had to buy some highly specialised gear to achieve that. That plus other expenses, Trudi reckons the entire trip will cost her $30,000.
"I always wanted to go to Mongolia. The horses and camels there are different from ours and the vastness of the terrain is so spectacular."
In 2000 she took part in a camel trek in Australia traversing the Simpson Desert, which consists mostly of sand dunes. "I trained eight months for that, because walking on sand dunes is tough and we needed to do 25km a day."
The experience had her hooked so much she worked for several years as a professional camelier in Australia and still goes back each year for 4-6 weeks to do camel trekking.
Her friends at Rangitikei Area Distance Riders are sponsoring her trip and last weekend held a fundraising event in Weber to help raise the compulsory £1000 destined for charity.
"It was a fantastic weekend," she said. "I was blown away by the support. Four friends organised the event while three others sorted the trail."
Trudi is giving her £1000 to the Mongol Derby's charity: Cool Earth. "We must give them £500, but I feel I can do more to help save the earth, so I am giving them all £1000."
The Mongol Derby is done annually by about 40 riders and riders have to apply to enter.
The entry fee is US$13,000 ($18,797), and then there is the compulsory £1000, flights, gear, and accommodation. It starts on August 8.
You can help Trudi by sponsoring her via: https://givealittle.co.nz/cause/mongol-derby-for-a-cool-earth. You can follow her adventure through: https://www.facebook.com/Mongol-Derby-2018-for-a-Cool-Earth
