CHAPTER II. 
GRAYSON'S FERRY, ON THE SAN JOAQUIN, TO FORT MILLER. 
SAN JOAQUIN RIVER AT GRAYSON’S FERRY.— TUOLUMNE RIVER.—ALLUVIAL LAND UNDER CULTIVATION.—MITCHELL’S BRIDGE.— 
A 
MERCED RIVER TO BEAR CREEK.— TABLE HiILLs.—HomizONTAL STRATA.—FossIL TREE.—FOOTHILLS OF THE SIERRA.— 
GRANITIC AND METAMORPHIC ROCKS.— CLAY SLATE.—QUARTZ YEINS.—GOLD.—SANDSTONE STRATA RESTING ON THE EDGES 
OF THE SLATES.—QUARTZ VEINS.—IRON oRE.—BunNs' CREEK.—FLAT-TOPPED HILLS.—BEAR CREEK.—SECTION OF THE 
HORIZONTAL STRATA.—SUN-CRACKS IN THE STRATA. —ANDALUSITE.—VIEW OF THE PLAINS OF THE SAN JOAQUIN.—GoLD.— 
FRESNO.—SNoW ON THE SIERRA.—FRESNO RIVER.—RicH soiL.—GRANITE.—SYENITE —Gorp. —TABLE-LANDS COVERED 
WITH LAVA. 
Grayson’s Ferry, July 18.—We crossed the San Joaquin at this ferry and landed on the 
eastern bank a short distance below the mouth of the Tuolumne river, which enters the San 
Joaquin from the eastward. Both banks of the river are low, and the western side is fringed 
with a fine grove of trees. The opposite side is, however, without timber, and the soil appears 
to be poor and sandy, supporting only a scanty growth of grass and weeds. 
At the time we crossed the river the water was not at its lowest stage, the stream being still 
swollen by the melting of the snow on the peaks of the Sierra Nevada. A large portion of the 
bottom-land of the river was therefore submerged, and the stream was much broader than is 
usual in the dry season. The current was swift and strong, and considerable greco of fine 
sand and mica were suspended in the flood. 
T'uolumne river.—Leaving the San Joaquin, we passed eastward along the south side of the 
Tuolumne and a short distance from its left bank. Its course over the plains was distinctly 
marked by the green timber along its bottom-land, and we encamped on its borders in a 
splendid grove of oaks. The size and beauty of these trees, and the luxuriance of other vege- 
tation, bore testimony to the depth and richness of the soil, and its adaptation for agriculture. 
This vegetation and timber is confined to a bench or terrace of the river, lower than the upper 
or barren plain, and yet slightly raised above the bed of the stream. The height of the sur- 
face of the plain above the river-bottom, or its first terrace, is variable. It was not clearly 
defined at our first camp, but, at the second, about 30 miles above the mouth of the river in the 
San Joaquin, it was about thirty feet high, and as we travelled up the stream I observed that 
it increased to a height, at one place, of nearly one hundred feet. 
The low river-bottom, bounded by the bank or terrace, is of variable width, and portions of it 
are cleared and cultivated. It is sometimes slightly overflowed during the season of floods. 
The regularity and the steep slope of the terrace are remarkable, the descent being often so 
abrupt as to be impassable. "These valleys, filled with green vegetation and trees, present an 
agreeable and striking contrast with the broad and nearly desert plains that they traverse. 
Mitchell's bridge, July 20.— We descended from the plain to the bottom-land of the river 
and camped. We found a wide belt of fine land under cultivation; corn, vegetables and 
