  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 cross-section 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.
