[CMake] Problem using find_library()

[Calder Coalson]

Sorry to bother everyone, but I have a mildly inexplicable problem
with the find_library function.  I won't bother you with the entire
code unless you ask for it, but here's a minimal example of the
relevant details:
set(OGRE_SDK_PATH "C:/OgreSDK" CACHE STRING "")
set(DEP_LIB_PATH "${OGRE_SDK_PATH}/lib")
find_library(OGRE_LIBRARY_REL names OgreMain paths ${DEP_LIB_PATH})
message(${OGRE_LIBRARY_REL})

This outputs OGRE_LIBRARY_REL-NOTFOUND despite the fact that
OgreMain.lib is located in C:/OgreSDK/lib .  Thanks in advance for
catching the stupid mistake I'm making!