I settled on a dog bone with crossovers at each end of the main to allow for two trains to take turns. The track will rest on 2x6 pine studs set on standard cinder blocks laid directly on the ground. The pine will last for several years without trouble, is cheaper and better for the environment than treated lumber. Additional track will be added later.
Scenic treatment will be a simple affair. My technique will be to allow anything to grow without prejudice to species - then to feather it to rail-height.
The entire affair will total about 12 feet in length. I had hopes of a slightly more elaborate track-plan, but LEGO had the audacity to become out-of-stock on RC track for the next 2 1/2 months! At right is the obligatory "before" picture. The ground is fairly open and level. The real challenge as I see it is harmonizing my creation with this wildly natural backdrop.