The course is on the sheep and beef farm run by Stewart and husband Andrew. It starts at their Rangitikei Farm Stay Woolshed 12km north of Marton and there are 3km, 5km and 8km options.
Although many of the obstacles are kept secret until the day, participants can expect the course to be built around natural resources on the farm including a floating island to crawl over, bogs to wade through and hills to climb.
"Everyone's favourites like the waterslide are still around but there are definitely some new obstacles that have been added."
Stewart said it is rewarding to be able to put on the event after such a tough year for everyone.
"The Mudder is about having fun. It's important to remember the reason The Mudder was created, to raise awareness for mental health.
"It's great to put on an event where people can come have a bit of fun. And of course, exercise is really good for mental health as well."
Stewart said she was looking forward to seeing everyone's crazy outfits and having a fun day out.
"The brighter, the better. I'm expecting people to go next level. Dressing up is a huge part of the day. We are looking forward to the fun."
The remaining tickets can be purchased at https://www.themudder.co.nz/.