I noticed an interesting post on the Civil 3D discussion groups. The LD complex linetypes are included with the standard Civil 3D install at this location.

\Documents and Settnigs \ User\Application Data\Autodesk\C3D 2008\enu\Support

The file contains the following linetypes:

;; AutoCAD Land Development Desktop Complex Linetype file
;; Version 1.0
;; Copyright (C) 1998 by Autodesk, Inc.
;;
*BARBWIRE_1, Barbed Wire Fence with spaces
*BARBWIRE_2, Barbed Wire Fence without spaces
*CHAINLINK_1, Chain Link Fence with spaces
*CHAINLINK_2, Chain Link Fence without spaces
*GUARD_L, Guardrail, posts on left
*GUARD_R, Guardrail, posts on right
*STOCKADE_1, Stockade Fence with spaces
*STACKADE_2, Stockade Fence without spaces
*STONEWALL, Stone Wall
*TREELINE_L, Tree Line left side
*TREELINE_R, Tree Line right side

Thanks to MAnderson for the tip.

Click here the original post on the discussion group.