  We measure the enclosed Milky Way mass profile to Galactocentric distances of
$\sim70$ and $\sim50$ kpc using the smooth, diffuse stellar halo samples of
Bird et al. The samples are LAMOST and SDSS/SEGUE K giants (KG) and SDSS/SEGUE
blue horizontal branch (BHB) stars with accurate metallicities. The 3D
kinematics are available through LAMOST and SDSS/SEGUE distances and radial
velocities and {\it Gaia} DR2 proper motions. Two methods are used to estimate
the enclosed mass: 3D spherical Jeans equation and Evans et al. tracer mass
estimator (TME). We remove substructure via the Xue et al. method based on
integrals of motion. We evaluate the uncertainties on our estimates due to
random sampling noise, systematic distance errors, the adopted density profile,
and non-virialization and non-spherical effects of the halo. The tracer density
profile remains a limiting systematic in our mass estimates, although within
these limits we find reasonable agreement across the different samples and the
methods applied. Out to $\sim70$ and $\sim50$ kpc, the Jeans method yields
total enclosed masses of $4.3\pm0.95$ (random) $\pm0.6$ (systematic)
$\times10^{11}$ M$_\odot$ and $4.1\pm1.2$ (random) $\pm0.6$ (systematic)
$\times10^{11}$ M$_\odot$ for the KG and BHB stars, respectively. For the KG
and BHB samples we find a dark matter virial mass of
$M_{200}=0.55^{+0.15}_{-0.11}$ (random) $\pm0.083$ (systematic) $\times10^{12}$
M$_\odot$ and $M_{200}=1.00^{+0.67}_{-0.33}$ (random) $\pm0.15$ (systematic)
$\times10^{12}$ M$_\odot$, respectively.
