Those focusing only on Nauvoo difficulties and deliberations for the Mormon exodus to “Zion” have overlooked the intense planning sessions at Winter Quarters on the west side of the Missouri River during the winter of 1846–47. Nauvoo was left in haste long before the final details of the westward march had solidified. Due to the weather, disorganization, lack of preparation, and recurring arguments over leadership, the Mormon vanguard took more than four months to cross Iowa, only to be again delayed by the call for the Mormon Battalion. With the inevitable decision to winter at the Missouri in the Council Bluffs region, Church leaders found the time to catch their collective breath and more thoroughly prepare for the mountain trek. This article details the plans, arguments, and decisions of that winter of 1846–47. At stake was far more than mere route plans; rather, basic questions of leadership and authority were being tested.