Hello from Oz, John!
We also had Lionel growing up in New York. For reasons similar to your own (we have two grandsons and a big back yard), we settled on G scale.
All of our track is screwed to bricks or concrete pavers. It cost next to nothing because we had lots of bits and pieces left over from various building projects. Digging out and installing a foundation this way is slow (we level everything), but it’s OK if you take it a bit at a time.
After a day at work, I find laying track foundation a good way to unwind. Bricks don’t lie, cheat or steal, they’re pretty quiet and more intelligent than many people.
Since the temp never gets to freezing in Perth, and our soil is sandy and therefore not elastic, the brick and paver approach works for us. How you lay your track should relate to the climate where you live and the type of soil you’re laying the track on. On clay soil in an area subject to freezing, the brick-and-paver approach makes little sense. If, like Bob, you live on a rocky outcrop in the middle of nowhere, using the brick-and-paver method would be tantamount to insanity.
Other questions, like vegetation (check out Steve’s pine needle photo - YIPPEE!) and animals in the neighbourhood (e.g., moose, elk, grandkids) might also have some bearing on the foundation you use for your line, but they’re peripheral. Climate and soil are the main factors.
Good luck, and have fun!
