Two hundred years ago, a 30-man US Army party-the "Corps of Discovery"-ascended the Missouri River and conducted the most extensive exploration yet attempted of the North American continent's interior. Their accomplishments in the two-year journey were remarkable, and bear testimony to the leadership acumen of Captains Meriwether Lewis and William Clark. The results were also a testament to the courage and fortitude of the soldiers they led. No successful operation, however, occurs in a vacuum. Detailed planning and preparation are often key elements in the eventual overall conclusion. In that vein, the preparations for the Lewis and Clark expedition were exhaustive. President Thomas Jefferson, father of the expedition, ensured Lewis was well prepared for his task by coaching, mentoring, and teaching the young officer for two years. Lewis and Clark then spent the better part of a third year planning and organizing for the journey. As a result, they had plans for almost every contingency imaginable. In addition, their mental preparation and agility enabled them to react to and take advantage of unforeseen circumstances. Major Donald Carr's Into the Unknown: The Logistics Preparation of the Lewis and Clark Expedition is a valuable study examining the key logistics components and considerations in the planning and execution of the mission. Modern logisticians will find themes in transportation, civilian contracting, indigenous (host nation) support, and others that still resonate today. Major Carr clearly demonstrates that Captains Lewis and Clark, in facing the daunting tasks of the great expedition, rose to the challenges and met them with ingenuity, detailed planning, discipline, leadership, and resolution-hallmarks worthy of reflection by today's junior leaders.