Referee for 22 Journals

Editorial Board, Open Journal of Discrete Mathematics (2011-Present)

Editorial Board, DIMACS Educational Modules Series (1997-Present)

Editorial Board, Journal of Discrete Mathematics (2011-2016)

Organizer, IntersectionFest; The Workshop on Intersecting Set Systems (2016)

Organizing Committee, Computers in Scientific Discovery 7 (2015)

Organizing Committee, Connections in Discrete Mathematics (2015)

Organizer, PebbleFest; The Workshop on Graph Pebbling (2015)

Advisory Council, Desert Garden Montessori School (2004-2014)

Organizer, 16th SIAM Conference on Discrete Mathematics, Minisymposium on Graph Pebbling (2012)

Organizer, Joint Mathematics Meetings Minicourse on Linear Optimization (2011)

Organizer, 2nd SIAM Canadian Discrete and Algorithmic Mathematics Conference, Minisymposium on Graph Pebbling (2009)

Program Committee, Jubilee Conference on Discrete Mathematics (2009)

Organizer, First Southwestern Undergraduate Mathematics Research Conference (SUnMaRC) (2008)

Organizer, 12th SIAM Conference on Discrete Mathematics, Minisymposium on Graph Pebbling (2004)

Director, First Arizona Mathematics Undergraduate Conference (AMUC) (2004)

Program Director, Society for Industrial and Applied Mathematics , Discrete Mathematics Activity Group (2000-2002)

Co-Director, Summer Teacher's Institute in Mathematics (2001)

Organizing Committee, 13th International Conference on Formal Power Series and Algebraic Combinatorics (2001)

Member, Arizona Mathematics Education Panel of Experts (2000-2001)

Editor, Society for Industrial and Applied Mathematics, Electronic Newsletter (1997-1999)

Education Director, DIMACS Research and Education Institute (DREI) , Graph Theory and Combinatorial Optimization (1998)

Steering Committee, Center for Discrete Mathematics and Theoretical Computer Science (DIMACS) , Research and Education Institute (1996-1998)