In this talk I will review recent work attempting to connect generic Calabi-Yau threefolds to those with elliptic/genus-one fibrations through simple geometric transitions. In particular, I will describe recent progress demonstrating that all known manifolds in largest known datasets of CY threefolds (the Kreuzer-Skarke threefolds constructed as toric hypersurfaces and the CICY threefolds built as complete intersections in products of projective spaces) are all connected to genus one fibrations through single geometric transitions.