22 unique boulders, each with diffuse, bump, displacement, and specular maps (where appropriate). All materials/maps assigned & ready to go. The only special thing about the file is all the materials are designed to be rendered with mental ray (Arch & Design material).
Each boulder can be fully customized by adjusting the turbosmooth (set low for distant renders, and high for close-ups), displace, noise, & bend modifiers; from 50 faces all the way up to any level your computer can handle. The displace (with bitmap) modifiers are kinda 'stuck' to the mesh in that you should only adjust the strength; all other displacement (& bend) modifiers can be easily changed to modify the overall look of the stone. This method is completely non-destructive and excellent for quickly populating large areas of customized stone.
The file 'landscape_stones_submerged.txt' contains all the geometry details that result from the current settings for the turbosmooth modifiers. Other than that, each object (37 total) is a simple 36 vertex, 50 face plane under a customizable modifier stack. That's why the max file is so small (1808 KB). But there's 'lots-o-maps' - that's why the zip file is so large.
Another similar file is available for full boulders. For that search for '6foot_boulders.zip.' Uses the same principle except with a box instead of a bent plane.