We present Yea Big, Yea High - a 3D user interface for surface selection in virtual environments. The interface extends previous selection interfaces that support exploratory visualization and 3D modeling. While these systems primarily focus on selecting single objects, Yea Big, Yea High allows users to select part of a surface mesh, a common task for data analysis, model editing, or annotation. The selection can be progressively refined by physically indicating a region of interest between a user's hands. We describe the design of the interface and key challenges we encountered. We present findings from a case study exploring design choices and use of the system.