Simplicial and cell complexes can be used as discrete models of complex relationships in three, or more, dimensions. This project explores their spanning trees, which are subcomplexes that are just big enough to reach the whole complex, yet small enough to avoid redundancy. Over the last decade, Dr. Duval has been working with collaborators from Brown University and the University of Kansas on these trees. The grant provides (1) travel support for Dr. Duval to meet with or host collaborators at UTEP; and (2) direct support to enhance the research environment of the UTEP Department of Mathematical Sciences.