Sources
Thick Clefthoof Leather is skinned from the clefthooves in Nagrand and from elekks at Ruins of Baa'ri.
As a leatherworking ingredient
[Bag of Many Hides]
[Clefthide Leg Armor]
[Drums of Battle]
[Enchanted Clefthoof Boots]
[Enchanted Clefthoof Gloves]
[Enchanted Clefthoof Leggings]
[Heavy Clefthoof Boots]
[Heavy Clefthoof Leggings]
[Heavy Clefthoof Vest]
[Leather Chestguard of the Sun]
[Leather Gauntlets of the Sun]
[Nethercleft Leg Armor]
Patch changes
Patch 6.0.2 (2014-10-14): Stacks to 200, up from 20.
Patch 2.0.1 (2006-12-05): Added.