Agreed. This is also a good tip for photographing people. If they are gazing into the distance, have the distance in front of their face as opposed to behind them.
OP: you show a good understanding of the rule of thirds. However, allow me to give you some general advice when photographic landscapes: you need some foreground interest, which is what the first image is missing. It can be anything, you can get down low and use the tips of the crops for example, a rock, something to separate the foreground and background and give a sense of depth. To give an example of mine:
http://flickr.com/photos/ozga/2625565950/
Some other general advice: the photos, in particular the first, could definitely to with a saturaiton and contrast boost.
Finally, keep in mind that the "rule" of thirds isn't somehting you ALWAYS have to follow. Don't try to force composition onto a photograph by thinking to yourself "if I imagined a tic tac toe grid and the points were here..." - just to whatever feels right. Often, I find moving the subject off-center, but not necessarily on one of the intersecting points works best. I say this because there seems to be too much of an emphasis on using this compositional aid all the time in beginner photographers.