When the Spaniards first visited the County, there were said to be thirty distinct tribes of Indians, each with its separate chief; while their language or dialect differed materially. That they lived on mussels, sturgeon, and game from the marshes, is evidenced by the remains found in the huge shell mounds distributed throughout the County. [Illustration: The Last of the Race.] What these mounds are and how they became so, is merely a matter of conjecture, although the scientists of the University of California and Stanford are revealing additional clues from time to time as new deposits are discovered. [Illustration: A Wood Interior.] In the Marin mounds have been found mortars and pestles, queer old pipes, beads of wampum, oyster picks, skulls, and in many instances entire skeletons, while the arrow-points testify to certain warlike propensities, although on the whole they were said to be peaceful tribes. [Illustration: Summer in the Redwoods.] The bows which they used with such celerity and skill were uniquely fashioned; the cord consisting of the nerves taken from a deer's back. The Marin Indians and in fact all the California tribes, dwelt in small huts built of willows with tules or rushes, and formed by taking a few poles, placing them in a circle, and finally weaving them together to a conical point, giving, when completed, the appearance of inverted baskets. They were usually constructed on the banks of streams, and, being small, were easily warmed in winter. The aborigines' knowledge of the proper treatment of disease was very limited. Roots and herbs were sometimes used as remedies but the "sweat-house" (temescal) was the principal reliance in desperate cases. [Illustration: A Charming Drive.] One of these sweat-houses was found on the Nicasio Rancheria, just over the Olompali Mountains. It consisted of a large circular excavation, covered with a roof of boughs, plastered with mud, having a hole on one side for an entrance, another in the roof to serve as a chimney. A fire having been lit in the center, the sick were placed there to undergo a sweat bath for many hours, to be succeeded by a plunge in the ice-cold waters of a neighboring stream. This treatment was their cure-all, and whether it killed or relieved the patient depended upon the nature of his disease and his constitution. [Illustration: Browsing.] It seems but fitting that this County, which formerly was a favorite rendezvous of the Indians, should derive its name from a famous chief of the Lacatuit Indians, who frequented the southern part of the Peninsula. Between the years 1815 and 1824 Chief Marin, aided by his people, is said to have vanquished the Spaniards in several skirmishes for supremacy. Being finally captured by his enemies, and making his escape, Marin took shelter on a tiny island in upper San Francisco Bay. This island being subsequently called after him, communicated its name to the adjacent mainland.