This little fern might be just the plant you're looking for to enhance your shady rock garden. Like its cousin western cliff fern, Rocky Mountain woodsia is at home in rocks, around rocks, growing out of rocks...pretty much any place where its roots can have a nice snug cozy fit. Unlike western cliff fern, this fern prefers shade and some moisture. 
 
This fern has classic dissected leaves and grows in a compact clump. Even well-watered specimens don't quite reach a foot in height. This species may go dormant if things get to dry, so don't panic if the leaves fade away in July and August. 
 
Plant with alumroot, raceme pussytoes, and lance-leaf or worm-leaf stonecrop.