A staged approach towards muon based facilities for Intensity and Energy Frontier science, building
upon existing and proposed facilities at Fermilab, is presented. At each stage, a facility exploring new
physics also provides an R&D platform to validate the technology needed for subsequent stages. The
envisioned program begins with nuSTORM, a"sensitive"sterile"neutrino"search"which"also"provides"
precision" neutrino" cross2section" measurements" while developing the technology of using and
cooling muons. A staged Neutrino Factory based upon Project X, sending beams towards the Sanford
Underground Research Facility (SURF), which will house the LBNE detector, could follow for
detailed exploration of neutrino properties at the Intensity Frontier, while also establishing the
technology of using intense bunched muon beams. The complex could then evolve towards Muon
Colliders, starting at 126 GeV with measurements of the Higgs resonance to sub-MeV precision, and
continuing to multi-TeV colliders for the exploration of physics beyond the Standard Model at the
Energy Frontier. An Appendix addresses specific questions raised by the Lepton Colliders subgroup of
the CSS2013 Frontier Capabilities Study Group.