A great reliance in propelling the keelboat, strange as it may seem considering the nature of Missouri River navigation, was the wind. A mast was rigged, with a square sail spreading about one hundred square feet of canvas, which often gave sufficient power to propel the boat against the swift current of the river. Unless the direction of the wind were altogether wrong the sinuous course of the stream would every now and then give an aft or quartering breeze. In some places the wind seemed to follow the bends, blowing up or down the river clear around. Thus Brackenridge relates that when Manuel Lisa’s boat, in June, 1811, was going around the Great Bend below Fort Pierre, where in the course of thirty miles the river flows toward every point of the compass, an aft wind was experienced all the way, and the entire circuit was made under sail. Some idea of sailing speed up the Missouri under favorable conditions may be gleaned from the fact that, on the day of passing the Great Bend, Lisa’s boat made seventy-five miles, a portion of the distance being made at night by the light of the moon. And on another occasion on the same trip Brackenridge records that “we had an extraordinary run of forty-five leagues from sun to sun.” [Sidenote: KEELBOAT SPEED.] Thus, by means of the cordelle and pole, the oar and sail, the sturdy keelboat worked and worried its way up the turbulent Missouri in the early days. It was a slow and laborious process at best. A good idea of its maximum accomplishment under rather unfavorable conditions is furnished by Manuel Lisa’s voyage, already referred to. It was made with an exceptionally fine boat, a picked crew, and the most untiring and energetic commander that ever ascended the Missouri. There was especial necessity for rapid progress, for it was of the greatest importance to overtake the Astorian expedition, which was a long distance ahead, before it should reach the dangerous Sioux country. The difficulties from wind and storm were greater than the average, and the rate of progress was not increased by any fortuitous aids. Lisa left St. Charles, 28 miles above the mouth of the Missouri, April 2, 1811. He overtook Hunt at 1132 miles, on the morning of June 11. He therefore made about 1100 miles in sixty-one days, or about 18 miles per day. This, however, was better than the average. A keelboat trip to the upper river was practically an entire summer’s operation. [Sidenote: LABORIOUS OCCUPATION.]