If you're still working on this world, there are instructions on how to place distant terrain in the CAW Walk Through (found here: http://www.thesims3.com/content/global/downloads/caw/CaW_WalkThrough.pdf -- Page 5, Section 7).
When you place it, it will not fit correctly, but you can use the X,Y,Z handles to get them into the position you want. If you want no ocean to be seen at all, then you can place multiple DTs around the map and adjust their placement so that the water can't be seen. It takes a little practice and a LOT of patience, but it is possible to make an inland town. It's also a great idea to use the angular rotation tool to spin the DT so that you can get it the way you want. Another option is to raise the level of all of the exterior edges to create a 'valley'. By placing rather large no-camera boundaries, you can get very good results.
Hope this was helpful! I'd dearly love to see this town finished -- particularly since Supernatural just came out and I'm not too big a fan of the in-game town.
