It's called the Growler Light Strike Vehicle:
It's top speed is 35 miles per hour, it's only 50 inches wide so it can fit in a small cargo plane and is designed to surmount an obstacle 12 inches high. It is based on Vietnam-era jeep technology, and uses some of the same parts. It is unarmored and so can't be used in urban environments. It's sole mission is to tow a mortar and haul ammo in uninhabited areas. The commercial version is $15,500 and a military model sold to the Dominican Republic was priced at $33,000.
The U.S. Marine Corps is paying $209,000 each. You may be shocked to learn that the company which makes them is run by a retired U.S. Marine Colonel.
I have a better option: mules. They cost about $3,000 each after training and can climb over obstacles greater than 12 inches. I don't know how much they can haul, but I imagine a team of 4 could pull quite a bit and you'd still be $197,000 ahead on cost. On the downside, they'd shit all over the place. On the upside, you could eat them if you get in a tough spot. Can't really eat your $209,000 jeep.