  In this work we explore multiple search strategies for higgsinos and mixed
higgsino-wino states in the MSSM and project the results onto the $(\mu,M_2)$
plane. Assuming associated production of higgsino-like pairs with a $W/Z$
boson, we develop a search in a channel characterized by a hadronically tagged
vector boson accompanied by missing energy. We use as our template an ATLAS
search for dark matter produced in association with a hadronically decaying
vector boson, but upgrade the search by implementing a joint likelihood
analysis, binning the missing transverse energy distribution, which greatly
improves the search sensitivity. For higgsino-like states (more than 96%
admixture) we find sensitivity to masses up to 550 GeV. For well-mixed
higgsino-wino states (70-30% higgsino) we still find sensitivities above 300
GeV. Using this newly proposed search, we draw a phenomenological map of the
wino-higgsino parameter space, recasting several complementary searches for
disappearing tracks, soft leptons, trileptons, and hadronic diboson events in
order to predict LHC coverage of the $(\mu,M_2)$ mass plane at integrated
luminosities of up to $3\,\text{ab}^{-1}$. Altogether, the full run of the
HL-LHC can exclude much of the "natural" ($\mu,M_2 <$ 500 GeV) wino-higgsino
parameter space.
