Pete's recommendation is to make an area containing loose smooth pea gravel (not crushed rock gravel) available to horses for at least a few hours a day. The area would need to be kept free of manure, debris, and loose dirt or it would become packed down.

There are different types of round gravel. Pea Gravel is usually about pea size. I happened to use larger gravel that is between 1/2 inch to 1 inch in diameter because it was available on the property. If I was buying gravel I would get smooth pea gravel.

Soft ground needs preparation; a wood frame helps retain pea gravel, and construction cloth will help keep gravel from mixing mixing with the subsoil

Manure sticks to gravel, so it'll be difficult to keep clean if built in an area that horses like to defecate, but I think I have a solution. My area drains well, so I will keep it picked out, and any that I can't clean out will get ground into dust that can be pressure hosed out.

The pile's on the way to the trough, and the direct route is a gravel-free lane between the fence and the gravel pile but they consistently walk through the middle of the pile, sometimes pausing to paw at it. I sense that it has a massaging quality about it.

My horses urinate in the gravel sometimes anyway, so I rinse it occasionally to eliminate ammonia buildup.

Gavilan loves his gravel!! He doesn't spend a lot of time standing still on it, but he and Shatirr both go out of their way to stroll through 5 or 6 times an hour.

I'm also using large rock to cobble an area large enough to feed the boys on, and placed large broken rocks around the tree, which they love rubbing on... I thought they'd stay off the sharp broken rock around the tree (I'm discouraging them from too much rubbing and chewing), but they still go stand in it!

This combination of gavels, rock and cobble buffs the horses soles to build callous while abrading the hoof wall the way a natural environment would. The cobbled surface allows water to run off and is easy to rake clean of manure and spoiled hay. Rocked surfaces can be occasionally rinsed to remove manure.

"Road base" is usually decomposed (crushed) granite with a mix of "fines" (powdered granite) and gravel. It's the same stuff that's used under asphalt roads.

There are different classes differentiated by the size of the gravel they contain. When I order road base in California, I usually get class 2.

When I use it in a paddocks that tend to be extremely muddy or soft, I prepare the surface by removing all organic material (manure, leaves and grass), then line the area with construction or landscaping cloth. This is inexpensive recycled plastic that allows water to drain but keeps whatever is on top of it from mixing with the ground beneath it.

Then I frame in the area where I want to put a road base pad with 2x6 boards to hold the base. I then fill the frame with enough road base to have it start out at least 5 inched deep , spread it out so that it is slightly higher at one end than the other (to encourage drainage), and water it thoroughly (so that water comes out the bottom of the frame) with a sprinkler.

Once it's watered I roll it repeatedly with a lawn packer or pack it down with a vibrating packer until its hard as cement. Then I rewater it and re-roll or pack it again.

If the pad is rolled hard and manure and organic material are kept off of it, it should last for several years. This pad sheds water nicely or drains if a puddle occurs and is great for feet.