Moguls are bumps in a ski slope formed when skierss cut grooves in the snow as they execute turns.

Once formed, a mogul tends to grow, as skiers will follow similar paths around it, further deepening the surrounding grooves. Since skiing tends to be a series of linked turns, moguls form together.

In most ski resorts certain runs are left un-pisted (un-groomed) to allow moguls to develop.

See also