This paper presents data structures that enable interactive editing of large-scale level-set surface models. The new approach utilizes spatial hashing to store a narrow band of voxels around the level- set interface, as well as a k-d tree to hold the model's display points that lie on the surface itself. This sparse representation of voxels and surface points lets us create and modify high resolution level- set models with modest memory requirements, while allowing fast data access/modifications and interactive graphics updates. The data structures also support out-of-the-box editing, i.e. no bounding box limits the surface editing region, a restriction common when utilizing 3-D arrays. We formally define the level-set representation and demonstrate its interactive performance and scalability through manipulation of high-resolution level-set surface models.