I'm not so sure these can really be called "HD". They're just blurred, over anti-aliased versions of the originals.
Plugin Version of Tim Vogels 'High-res Landscapes v1.1' for Marathon Infinity.
-For screen shots and details refer to the original MOD. -Original Readme enclosed -Released under permission
INSTALL INSTRUCTIONS: 1) Cut & Paste 'High-res Landscapes v1.1 (M3).zip' into your 'Plugins' folder in the AlephOne Folder. (Create the folder if you don't have one)
2) Start AlephOne.exe and go to Preferences->Environments->Plugins (Click to Enable/Disable Plugins)