What is an upk file and how do I open an upk file?
UPK files are used by Unreal Engine 3, a free gaming engine used to develop games such as Unreal Tournament 3, Mass Effect, Mirror's Edge, and BioShock. UPK serves as a file container which includes various types of game files like 3D models, textures, maps, music files, game settings, and other files. UPK files are used to load on-demand content while playing a game. They can be created and edited using the Unreal Development Kit.
Relevant upk file links:How to open upk file on Youtube
How to open upk file on Wikipedia
How to open upk file on Microsoft.com