Seriland, the home from time immemorial of the Seri Indians, lies
in northwestern Mexico, forming a part of the State of Sonora. It
comprises Tiburon island, the largest and most elevated insular body in
Gulf of California, together with a few islets and an adjacent tract
of mainland; the center of the district being marked approximately by
the intersection of the parallel of 29° with the meridian of 112°.
The territory is divided by the narrow but turbulent strait, El
Infiernillo. It is bounded on the west and south by the waters of the
gulf with its eastward extensions to Kino bay, on the east by a nearly
impassable desert, and on the north by a waterless stretch of sandy
plains and rugged sierras 50 to 100 miles in extent.
Tiburon island is about 30 miles in length from north to south and 12
to 20 miles in width; its area, with that of the adjacent islets, is
barely 500 square miles. The mainland tract held by the Seri is without
definite boundary; measured to the middle of the limiting desert on
the east and halfway across the waterless zone on the north, its area
may be put at 1,500 square miles. To this land area of 2,000 square
miles may be added the water area of the strait, with its northern and
southern embouchures, and the coastwise waters habitually navigated by
the Seri balsas as far as Kino bay, making half as much more of water
area. Such is the district which the Seri claim and seek to control,
and have practically protected against invasion for nearly four
centuries of history and for uncounted generations of prehistory.