At length, on the third of July, General Sully put the First Brigade in motion for the mouth of Long Lake River, distant about one hundred miles, and, after instructing the Second Brigade to proceed thither also on the next day, he set out himself on the _Island City_ to examine the river banks for a suitable site on which to build the new fort. As an escort for the boat he took a company of troops, and most of the members of his staff also went with him; but Al remained with the column, as his duties demanded his presence there. The marches were long but not exhausting, and by the eighth of July all the forces were assembled on the Missouri a short distance above the mouth of Long Lake River. Directly opposite, on the west bank of the Missouri, was the site on which the General had decided to build Fort Rice, as the new post was to be called. The location was an ideal one. It was a level tableland with a permanent bank along the river nearly one hundred feet high, and behind it rose a majestic range of sandstone bluffs, which, just below the post swept out boldly to the brink of the Missouri and followed it down to the mouth of the Cannonball River, eight miles south. Along the base of the bluffs extended a long, narrow belt of heavy timber, and another and much larger forest covered the wide valley above the post. Immediately in front of the latter the river was narrow, insuring a good crossing at nearly all seasons, its only disadvantage being that, owing to the high bank on which the fort stood, the ferry and steamboat landing had to be made about half a mile down stream. On the arrival of the army, a ferry, consisting of a long cable stretched from bank to bank across the Missouri, on which a flatboat was guided back and forth, was immediately put in operation. Some of the troops, including the Dakota Cavalry, crossed on it and went into camp near the site of the fort. The steamers were then unloaded and put to work crossing the rest of the troops and the wagon-train, and the army was soon all assembled on the west bank. Two sawmills, one operated by a steam-engine and the other by horse-power, the entire equipment for which had been brought along, were now started and began rapidly getting out building materials, the timber being brought from the near-by forests. Great cottonwood logs for the walls were squared to dimensions of six by eight inches, and planks and boards were sawed for the interior work. The stockade, with bastions on the northeast and southwest corners, was also built of cottonwood.