Local standard of rest UVW velocities of sources in our Keck/NIRES sample, along with comparison velocities of nearby late-L and -T dwarfs from C.-C. Hsu et al. (2021; gray dots). Symbol colors segregate subdwarf candidates (magenta), metal-poor comparison sources (black circles), and metallicity benchmarks (blue stars). In the upper-left, lower-left, and lower-right panels, we compare pairs of velocity components, with dashed lines indicating the 1σ velocity dispersion spheres for chemically selected thin disk, thick disk, and halo stars (in increasing size) based on the APOGEE and Gaia DR2 compilation of B. Anguiano et al. (2020). The upper-right panel displays a Toomre plot with circles indicating total speeds in steps of 100 km s⁻¹. In the plots containing the V velocity, we indicate the threshold between prograde and retrograde motion in the Galactic frame of rest (i.e., L_z = 0) by the dashed magenta lines at V = −232.8 km s⁻¹ (P. J. McMillan 2017). We also show schematic regions in the Toomre plot for the Gaia-Enceladus (red), Thamnos (cyan), and Helmi streams (magenta) based on H. H. Koppelman et al. (2019) for velocity pairs where these populations are distinct. Sources discussed in the text are labeled.