Folk wisdom of the state of Montana asserts that Flathead Lake, located in the state's northwest corner, is the largest natural freshwater lake west of the Mississippi. But what does it mean to be the "largest?" And, how does one respond to Californians' claims that Lake Tahoe, located on the California-Nevada border, is the rightful holder of the title? Situating this question in the context of a controversy gives meaning and purpose to measurement explorations while providing students with a rare opportunity to engage in mathematical modeling in geometry. The purpose of this article is to share a modeling task that the authors developed, one appropriate for middle and high school classrooms, and demonstrate, by using results obtained from implementation, that modeling tasks can be powerful tools in extending and connecting students' mathematical thinking. The authors begin by describing modeling and its place in the curriculum and standards. Then they transition into their task with descriptions of student solutions, classroom discussions, and important teaching considerations.