July 28 - August 1, 1853
Preparing to depart from the Assiniboine Camp, Stevens formed a party consisting of Mr. Lander, Dr. Suckley, Mr. Burr, and Corporal Rummell, who were fitted out for a journey to Pierced Rock on the Mouse river. They were tasked to explore the White Earth river; to make a thorough examination for coal and iron. They were further instructed by Stevens to explore the White river and surrounds as well as the Côteau du Missouri. From thence, to the 49th parallel and take a detour to the northwest to arrive at the Yellowstone in four days. Their surveys were to include barometrical observations, elevations, depressions, valleys, etc. in order to secure the best possible profile of the region.
Traveling 11 to 23 miles per day, the several days journey was primarily through rolling and hilly areas with stony knolls. There were small tributaries linked to Muddy Creek and scattered areas of trees. Also noted were a number of dry water courses that were probably flowing during spring and winter rains. On the 31st of July they had made a noon stop at Painted Wood creek, about 10 ½ miles from their camp where they were joined by two Assiniboine’s on their way to Fort Union to purchase tobacco and other sundries. The remainder of their day’s progress was a gradually changing landscape of harder prairies and a gradual but steady ascent, in view of the hills marking the Yellowstone; roughly 6 miles distant. Pitching their tents, they made camp and were soon joined by two other survey groups returning from their appointed tasks.
One problem they had been facing over the last few days was the scarcity of wood for fires, so they were using buffalo chips (dried buffalo dung) for fuel. Unfortunately, it appeared that there ha been fire the previous spring and buffalo chips were no longer easily available. Being unable to cook, Stevens ordered that pemmican be issued for their evening meal.[i] As was the practice when the trains arrived closer to a source of supplies such as Fort Union, provisions were inventoried and a list made of needs to be obtained from the fort.
August 1, 1853. Several individuals sent out to obtain provisions returned from Fort Union and the group proceeded on their journey toward the fort after marking another line. “About half a mile further we came in sight of the Missouri river, and the whole party gave three cheers as its beautiful bluff banks, dotted with timber, came in view.”  Stevens was then joined by Lieutenant Donelson Grover, who gave his report of the trip from Pike Lake which included the beauty of Lake Traverse and his experiences surveying the Missouri river.
The Lieutenant recounted their trip near the Butte de Morale, a prominent landmark, and his surveys of the Mouse river.
The configuration of Mouse River valley, as well as of its tributaries, resembles that of the Shyenne. High ridges divide the plateau bordering the stream from that extending into the prairie, with coulées intersection it and opening into the river on the one side, gradually growing imperceptible as they make into the prairie on the other. The general course of the river, and of its principal branch, the Riviere des Lacs, is nearly parallel to that of the Missouri, for the distance we followed it…and in the examination for a good passage for the wagon train, secluded spots were found where beetling crag [rocks that stick out; stand out] and winding stream, venerable trees and greenest sward [expanse of short grass] combined in scenes of much picturesque beauty. 
“Near Mouse River” lithographic print by Stanley Del
The distance from Mouse River to Fort Union, as they travelled, was 118 ¼ miles. They crossed the Grand Côteau, “a collection of high, strong, and barren knolls, with great numbers of small ponds lodged between the hills. Scarcely any wood is to be found, except a little on white earth river and its branches; but as water and grass are usually plentiful, this ridge will become a good grazing country.”
We will pick up the journey at Fort Union in the next installment of the series.
[i] Pemmican: A paste of dried and pounded meat mixed with melted fat and other ingredients, such as berries, originally made by North American Indians.