About Loading and Unloading LAS Files
LAS files can be in a loaded or unloaded
state within a
LIDAR Layer. In an
unloaded state

the LAS file is uninitialized in the layer and no points will be retrieved
from the LAS file or displayed in the map. In a loaded state

the LAS file is
initialized within the layer and will return or display points if
the map's display overlaps the extent or
boundary
of the file. The number of loaded LAS files do not affect the display
performance of the LIDAR Layer.
Note: A noticeable pause will occur when opening an MXD document
containing a LIDAR Layer with numerous loaded LAS files.