Expeditions: A MudRunner Game

I would start with downloading the Mega Bus from the mod browser as it makes it easier to traverse the terrain.

I would use the free Roam in Arizona to work on progress towards this. You will need to spawn at the field base operations headquarters. As you spawn in you want to go as far left before the water and there will be a flat area you can start making progress towards this achievement.

Here is a map of where to go:
https://imgur.com/nuHlE39

All credit goes to l BlackBrian7 l for the image.