At my brother in law farm there is a dirt road, no rock, nothing but hard packed dirt. This is in a flood zone of the Ohio river so it gets easily 5-6 feet of water on it every late winter when the river come up. Give it about 2 weeks after the water recedes and you can drive a combine on it and only leave tire tracks. That’s how hard packed dirt can get. In the summer it turns to a fine powder a couple of inches deep but still hard underneath. Roads been there since before the civil war as we have photos of troops marching on it.