Efficient rendering of large digital elevation models remains as a challenge for real-time applications. The direct use of hardware tessellation has limited applicability for managing level of detail of large models. Although the graphics hardware is capable of controlling the resolution of patches in a very efficient manner, the whole patch data must be loaded in memory. This compromises the scalability of GPU-based naive solutions for controlling level of detail. In this work, we propose an efficient and scalable new algorithm for large digital elevation models. Our proposal effectively combines GPU tessellation with CPU tile management, taking full advantage of GPU processing capabilities while maintaining graphics-memory use under practical limits. We also propose a technique to manage level of detail of aerial imagery mapped on top of elevation models as textures. Both geometry and texture level of detail management run independently, and tiles are combined with no need to load extra data. The proposed level of detail management is then extended to handle model with irregular border and holes.