What is the setting in the novel, The Lone Sentinel?

The Lone Sentinel is set in an unspecified future after "the last war" on Earth, when earthlings have settled the planet Azure and attempted to recreate conditions on Earth, with which they have lost all contact and which is probably extinct.

The Lone Sentinel compound—where the novel's action takes place—is the most remote of these steel towers whose beams protect the biosote fields from the birdlike struckies and the molelike borers. This sentinel, bounded by the Green Grass Ridge on the south and the wilderness on the north, is hundreds of miles from the settled area of New Province.