The robust hoof shape needed for today's riding is modeled after the mustang hoof found on horses wandering in hard, rocky areas like Nevada and Arizona.

In this environment, the hoof is worn by the horses' constant movement. The edges of the hoof from the toe to the "quarters" (the sides of the hoof wall at the base of the hoof) become rounded by loose soil & rock. These rounded edges enhance stability in off-road conditions, deflect rocks & dirt, & enhance traction.

The term Mustang Roll refers to this rounded edge, a characteristic that ultimately shapes the rest of the hoof with movement.

The "quarters" take on a scoop-shape that accentuates traction, absorbs concussion, & allows loose matter to escape to the sides of the hoof as the hoof descends in a weight bearing stage.

A hoof shaped by a loose rock environment has a pronounced scoop in the sides, a hoof shaped by work on flat surfaces (like carriage horses) have minimal scoop.

The sole on a natural hoof becomes concave towards the frog; the amount is dependent on breed & conditioning.

The heel/bar junction at the back of the natural hoof is also calloused & shiny. The heel bulbs & frog are tough & expand to absorb concussion & increase traction.

In soft, wet environments, abrasion doesn't occur easily so the natural hoof wall flair's& chips off, the frog gets soft & the dead sole becomes white & chalky so that minimal activity will result in shedding.

When living conditions don't include dozens of miles of movement over rock & dirt each day, trimmers can shape a natural hoof manually, and riders then finish the trim by riding over such terrain, or by providing a hoof-building environment that includes rock, pea gravel or other abrasive materials.

A un-maintained hoof will begin to flair, chip, crack, & flake in its attempts to shed excess wall & remain sound.

When a shod hoof has cracks, white line separation, flair, coronet distortion & chipping, the hoof wall is trying to get to a natural length.