UV a big land

I was trying to uv a big land, so it has grass, mountains, and falls off into a giant cliff. What I did was, in photoshop, I made the uv image REALLY REALLY big. It was over 4 thousand pixels wide, and tall. I made it so big so when I look at the ground it is still a good resolution. Anyways, I was wondering if there was a better way to do this. I don’t think a huge texture was the right way to do it.

How about a bunch of smaller, high-res textures–with subtle colour changes provided by a large procedural cloud texture–mapped onto a couple material nodes and blended together by a series of low-res alpha maps?

Woah, that flew by my head. I’m still new to blender. Let me rephrase my question. What is the best way to make a land with different componets, like mountains, grass, dirt.