64 EXPLORATIONS FROM A. D. 1843 To a. D. 1852. 
within ten miles of its mouth, when they left the river, and, crossing a basaltic ridge, struck 
the Colorado Chiquito, down which they travelled until they were opposite the northern end of 
the San Francisco mountains. Here they left the river and travelled southwest, around the 
base of the mountains, to Leroux Spring. Leaving this they passed around the southern base 
of Bill Williams" mountain, and thence pursued a course a little north of west, over a broken, 
basaltic, and barren country, to the head of Yampai creek. From this point they travelled 
westward to the Great Colorado, at the head of the Mohave valley; thence down the valley of 
the Colorado to Fort Yuma, and thence by the usual emigrant road over the Colorado desert, 
by Warner's Pass, to San Diego, California, where the party was disbanded. | 
RECONNAISSANCE OF THE COLORADO RIVER, BY LIEUTENANT DERBY, TOPOGRAPHICAL ENGINEERS, 1851. 
The report of this forms Senate Ex. Doc. No. 81, 1st session 31st Congress, and is accom- 
panied by a map, on a scale of 4 miles to an inch, of the Colorado river from its mouth to Fort 
Yuma. Lieutenant Derby was supplied with a sextant and chronometer. 
On the 1st of November, 1851, he sailed from San Francisco on board of a schooner carrying 
provision for the garrison at Fort Yuma. Doubling the southern extremity of Lower California, 
he passed up the gulf to the mouth of the Colorado, and thence (the vessel drawing 8 feet) to 
Howard's Point. Above this he ascended, in a small boat, to Heintzleman's Point, about one- 
third of the distance from the gulf to Fort Yuma, where he met Major Heintzleman. This 
officer furnished him with a sketch of the river between Fort Yuma and the place of meeting, 
and from this point he returned to San Francisco. 
RECONNAISSANCE OF LIEUTENANT WOODRUFF, TOPOGRAPHICAL ENGINEERS, 1852. 
. Lieutenant I. C. Woodruff, Topographical Engineers, made a reconnaissance, in 1852, of a 
portion of the Kansas river; of Walnut creek; of Pawnee Fork; and of other streams lying 
between the Smoky Hill Fork of the Kansas and the Arkansas rivers. "These examinations 
were made for the purpose of selecting proper sites for military posts. The map and report 
prepared by Lieutenant Woodruff have never been published. "The former was made from 
compass notes and estimated distances, checked by the astronomical determinations of Captain 
Frémont and Major Emory. 
EXPEDITION TO THE SOURCES OF RED RIVER, BY CAPTAIN R. B. MARCY, UNITED STATES INFANTRY, 1852. 
The report of this expedition forms Senate Ex. Doc. No. 54, 2d session 32d Congress, Ho. 
Ex. Doc. 1st session 33d Congress, and is accompanied by numerous illustrations and by two 
maps, one of which exhibits the country from the 91st to the 114th meridian, lying between 
the 31st and 38th parallels, drawn on a scale of 24 miles to an inch; the other, on a scale of 
10 miles to an inch, shows the country surrounding the sources of Red river. 
Captain Marcy was assisted by Brevet Captain G. B. McClellan, Engineers, who made 
astronomical observations for latitude and longitude by means of a sextant and ''pocket lever 
watch." The routes were mostly measured with an odometer, and observations were taken 
with a barometer. Dr. G. G. Shumard accompanied the expedition as surgeon and geologist. 
Starting on the 2d of May with his company, Captain Marcy marched to Red river, at the 
mouth of the Little Witchita, and up the right bank of the latter stream to the mouth of the 
Big Witchita, where they crossed Red river. Proceeding westward, between Red river and a 
branch of Cache creek, they struck the north Fork of Red river at the west end of the Witchita 
mountains, and followed that stream to its source in the Llano Estacado. Here an excursion 
