Crazy Horse Monument, South Dakota Looking at a 1/300 scale model for the Crazy Horse Mountain Carving, notice the actual mountain carving at the head of the horse. Nebraska / South Dakota State Line to the Black Hill National Forest Recration Area Black Hills National Forest stretches for 1.2 million acres, offering outdoor adventure like hiking, biking and camping amidst stunning scenery. Find grassy mountain meadows, towering granite peaks, deep canyons, cascading trout streams and clear, clean lakes.