ID:1294925
 
(See the best response by Pirion.)
i'm making a large map, and am using several map files to do this, the reason being is that if i could include the map sector when the player enters it and then exclude it after, it'd reduce lag from the moving mobs i'd like to include, i've got no problem with the map resetting afterward
Best response
You pretty much described SwapMaps from LummoxJr. The maps can be saved and loaded at runtime.

http://www.byond.com/developer/LummoxJR/SwapMaps
Thanks!