Ground objects without visible edges?

Hey guys- I’m working on learning/teaching myself Blender, and I’m really excited to finally start participating here! (I’ve used this site before to get help, it’s awesome.)

I’m wondering about how you guys make ground objects for larger scenes. I feel like you can have one gigantic ground object for the whole scene and it will obviously be smooth and unified… but that really only works if you’re modelling Iowa or another place with flat, rolling, ground. The project I’m working on right now has a TON of variation and vertical change in the ground, and one object would be very unwieldy. What I’ve been doing is making smaller ground objects and then positioning them together- if there’s a weird edge, I just move the vertices so it’s invisible. It works, but it feels clunky and sloppy. Any suggestions are greatly appreciated!!