Prehistoric terrace farmers inhabited the Gavilan for centuries without degrading it.

Evidence

There once were men capable of inhabiting a river without disrupting the harmony of its life. They must have lived in thousands on the Gavilan, for their works are everywhere. Ascend any draw debouching on any canyon and you find yourself climbing little rock terraces or check dams, the crest of one level with the base of the next. Behind each dam is a little plot of soil that was once a field or garden, subirrigated by the showers which fell on the steep adjoining slopes. On the crest of the ridge you may find the stone foundations of a watch tower; here the hillside farmer probably stood guard over his polka-dot acrelets. Household water he must have carried from the river. Of domestic animals he evidently had none. What crops did he raise? How long ago? The only fragment of an answer lies in the 300-year-old pines, oaks, or junipers that now find rootage in his little fields. Evidently it was longer ago than the age of the oldest trees. — Aldo Leopold, A Sand County Almanac, 532

Categorization

• XREF: Textbook example of reading disturbance history from present landscape structure — the reader’s own polyad method — dating abandonment by oldest tree ages. — connects to: Cattle and tourists will dismantle the headwater terraces Indians built. — Aldo Leopold, A Sand County Almanac: With Other…, 535
• SHARE: A reader teaching landscape interpretation could use the terrace-plus-tree-age dating example directly.
• ADDENDUM: Directly supports the trees-as-infrastructure essay’s theme: stone check dams as ancient land-use infrastructure readable in today’s ecology.