Using FSX and Vista I have installed "North american Landclass 1.1" and "World Terrain Mesh FSX"I note that "Ultimate Terrain X USA" is now available but am concerned that it will clash with one of the other above sceneries.Is there a danger in using more than one scenery add-on or will I simply be getting the best from each?Cliff

Ultimate terrain shouldn't clash with most addons. This IMO is a must have. They give detailed layout for coasts and lakes and rivers. UT has its own Land class which is nice. But their document has instructions on how to use other landclass files with it as well.Add ASX (Active sky for FSX) to this and FSGenesis Terrain meshYou have a nice setup for the whole US.Now, add specific photo detailed scenery over this like Megascenery if you want.Manny

Thanks Manny. I'll follow your advice.Regards..............Cliff