  We discuss the detection in the Outer Solar System Origins Survey (OSSOS) of
two objects in Neptune's distant 9:1 mean motion resonance at semimajor axis
$a\approx~130$~au. Both objects are securely resonant on 10~Myr timescales,
with one securely in the 9:1 resonance's leading asymmetric libration island
and the other in either the symmetric or trailing asymmetric island. These
objects are the largest semimajor axis objects with secure resonant
classifications, and their detection in a carefully characterized survey allows
for the first robust resonance population estimate beyond 100~au. The detection
of these objects implies a 9:1 resonance population of $1.1\times10^4$ objects
with $H_r<8.66$ ($D~\gtrsim~100$~km) on similar orbits (95\% confidence range
of $\sim0.4-3\times10^4$). Integrations over 4~Gyr of an ensemble of clones
spanning these objects' orbit fit uncertainties reveal that they both have
median resonance occupation timescales of $\sim1$~Gyr. These timescales are
consistent with the hypothesis that these objects originate in the scattering
population but became transiently stuck to Neptune's 9:1 resonance within the
last $\sim1$~Gyr of solar system evolution. Based on simulations of a model of
the current scattering population, we estimate the expected resonance sticking
population in the 9:1 resonance to be 1000-4500 objects with $H_r<8.66$; this
is marginally consistent with the OSSOS 9:1 population estimate. We conclude
that resonance sticking is a plausible explanation for the observed 9:1
population, but we also discuss the possibility of a primordial 9:1 population,
which would have interesting implications for the Kuiper belt's dynamical
history.
