METHOD OF COMPILING THE MAP. 107 
description of the Muscle Shell river in Governor Stevens’ report, and Captain Clarke’s descrip- 
tion of the Yellowstone in Chapter 33 of ‘‘ Lewis and Clarke’s Travels," that they are the same 
river, and also that the branch up which Lieutenant Mullan travelled when he left the Yellow- 
stone, is the one Captain Clarke calls Shield's river. I have so taken them.* The route 
of Captain Clarke from the source of the Jefferson Fork of the Missouri to the Yellowstone and 
down the latter, has been put in so as to conform to the points of his route تست‎ by 
Lieutenant Mullan’s and my own reconnaissances. 
The survey of Captain Reno, from Big Sioux river to Mendota, was reduced so as to conform 
to the Land Office work. The reconnaissance of Captain Sully, in 1855, from Fort Ridgely to 
Fort Pierre, was made to conform to the positions obtained from Mr. Nicollet. 
Captain Pope adopted Major Long’s position of the Pembina settlement on the Red River of 
the North, but he moved the position of the junction of the Red river and the Bois des Sioux 
about 12 to the east of it... Governor Stevens and Captain Simpson’s surveys indicate that 
Captain Pope’s work, between the Red river and the Mississippi, is crowded by at least 12’ more 
than it should be. I have therefore retained Major Long’s position of Red river and of his 
route to Lake Winnepeg, and thence to Lake Superior. Captain Pope's map was reduced so as 
to make his route agree in longitude with that of Major Long wherever they erossed.t From Mr. 
Nicollet's map has been taken the sources of the Mississippi, and the lakes, &c., between it 
and the Crow Wing river; which latter was taken from Captain Simpson's survey. The posi- 
tion of many of the lakes given by Mr. Nicollet in this neighborhood must have been derived 
in some uncertain way from the Indians, as many of them cannot now be recognized. The 
attempt has been made to retain for these lakes the names of the eminent scientific men with 
which he adorned the map of this region; but it is probable that, as the country becomes 
inhabited by white men, these names will have to be replaced on our maps by the more common 
ones of the country. Mr. Nicollet's map (I know not on what grounds) put Red lake consider- 
ably to the west of the position given it by Major Long; but the latter I have adopted, as 
recent examinations show it to be more probably correct. 
The boundary between the United States and British Possession has been taken from the 
maps of the surveys of the Northwestern Boundary Commission, from Lake Superior to Rainy 
1۵9 ee 
Xi uto. Abbot's Pacific railroad maps of Oregon and Northern California I have adopted 
exactly as prepared by him. 
Fort Vancouver was placed by Wilkes in longitude 123° 193'; and this was adopted by Capt. 
Frémont on his map of 1848. In Frémont's map of 184243 and '44, the longitude of this 
point is taken at 122? 413’. Captain McClellan adopted 122° 193' on his map of explorations 
in the Cascade mountains. Mr. Lambert, on making Governor Stevens’ map, took it 122° 40’. 
But the Land Office surveys, in connexion with the Coast Survey, show the longitude of Fort 
Vancouver to be 122° 323’, which we have adopted. This position is near a mean between 
that first given it by Captain Frémont and that by Captain Wilkes. Lieutenant Abbot’s posi- 
tion for the Dalles is 120° 58. Governor Stevens’ map has it 120° 53’, which is the same as 
on Wilkes’ and Frémont’s maps. Lieutenant Abbot places the Cascades in about longitude 
121° 42’; Frémont, 121° 36’; Wilkes, 121° 57’; which last was adopted by McClellan and 
* See foot note to page 68 of this Report for a discussion of this subject. 
+ This portion of the map, as first reduced and engraved, is erroneous in moving tlie whole of Red river to the west 12' to 
accord with Governor Stevens’ work. This would have been accomplished by adopting Major Long’s work as above. 
