Clark's column consisted of 1,700 men in his own brigade and that of Colonel Sidney D. Jackman, as well as part of Harris's Missouri Battery. Clark and Jackman were selected for the operation, as they were local residents. The column crossed the Missouri at Arrow Rock on the 14th. After hearing rumors that the garrison of Glasgow had a "tin-clad boat", Clark asked Price for more artillery. Since the river at Glasgow was narrow enough for artillery to effectively fire across it, Price sent Shelby with 125 men and part of Collins's Missouri Battery to a point across the Missouri from Glasgow. The Union garrison was initially a small force under the command of Captain John E. Mayo, but it had been reinforced on October 13 by part of the 43rd Missouri Infantry Regiment under the command of Colonel Chester Harding. The Missouri infantrymen had been temporarily stranded when the steamboats they were on ran aground. Once the ships were freed, they went downriver to Glasgow, where they unloaded the Missourians and supplies. One of the ships, "Benton", returned to Jefferson City, while the other, "West Wind", stayed at Glasgow. Contrary to the rumors heard by Clark, "West Wind" was both unarmored and unarmed.