I'm having an issue where distant textures on landscape and structures seem to be bugged. For landscape, where rock formations are supposed to appear (good example being the cliffs near Tenpenny Tower, but any similar 'rocky hills' area is the same) I see a sort of black ribbon-like texture that almost looks like a twisted up train weaving in their place. A specific type of building like the RobCo building and similar also have a strange red texture.

This one shows the red and white RobCo building: http://s775.photobucket.com/albums/yy37/the-cemm/?action=view¤t=ScreenShot11.jpg
Now I'm closer in and the RobCo building is correctly textured but the cliffs are still a mess: http://s775.photobucket.com/albums/yy37/the-cemm/?action=view¤t=ScreenShot13.jpg
A closer look at the cliffs rock formations problem: http://s775.photobucket.com/albums/yy37/the-cemm/?action=view¤t=ScreenShot14.jpg
Now some of the cliffs are loaded correctly while some of the problem is still visible: http://s775.photobucket.com/albums/yy37/the-cemm/?action=view¤t=ScreenShot16.jpg

Once I get close enough for near textures to load, the buildings are reloaded to look like their proper selves and the rock formations appear as they should. This problem just appeared in my game a few days ago and I'm trying to track down what is causing it. I've tried uninstalling recently added mods and that didn't fix it.

Does anyone have any ideas what to do or what is going wrong here? I'd appreciate any help or guidance.

Do you know if any of your latest mod downloads include .dds or .tsa graphic files? If a mod has installed graphic files that overwrite default LOD textures then simply disabling or removing the associated .esp file would not make them go away.

I went back and removed every mod in FOMM except for the Fallout.esm and it didn't fix the issue.

Anyone have any other ideas of what might be going on with these graphical glitches? It's got to be texture related right? Something going wrong with the distant textures before I get close and they update to higher detail?

Argh, disregard my last post as I completely misread what you posted. I tried to edit it but no longer can apparently.

So I need to go back through recent mod installations and look for mods that specifically added LOD textures and then manually remove those textures in addition to disabling the mods themselves to see if that fixes the issue?

Can I at least narrow it down to specific kinds of textures that would cause this problem? Like, only LOD textures I hope? For example, adding a companion mod that only adds weapon, clothing, body textures or similar wouldn't cause massive distant landscape/structure texture distortions right?

I've never added graphic files for hills, but have had to create some files for object LODs. They were in .tga format. Might try looking for them first.

They may also be in the Source directory which is not in your FO3 directory. \Source\Textures TGA\Landscape

I had the exact same problem. I found the culprit in Textures\Landscape\LOD\Wasteland. There was a folder in there called Blocks with two files inside it. I moved it to my desktop, fired up the game and everything was back to normal. I've looked through half of my mod archives and that folder doesn't exist in any of them. I don't know where I picked it up.

I just found it while digging through one recently downloaded mod after another tonight. It appears "Lighthouse 1_1" that adds a lighthouse near the Citadel was the culprit. In the .rar is the lighthouse.esp and then the texture folders you noted above (Textures\Landscape\LOD\Wasteland\Blocks\) that includes two .dds files. Removing Wasteland.Buildings.dds and Wasteland.Buildings_n.dds and disabling the lighthouse.esp mod in FOMM did the trick and fixed my landscape glitches.

It would be kind to let the author of the mod know about your discovery.

Thanks again for your help BadPenney! I did go and send them a private message on the Nexus just so they knew. I looked through the comments and it doesn't appear anyone else is having these issues. I'm kind of stumped though because as far as I can tell these two .dds files weren't being used by anything else, so I'm not sure what might have been in conflict with another mod that would have led to this. That is almost certainly just my own ignorance with the GECK and how FO3 mods work in general though.