  As the earliest stage of planet formation, massive, optically thick, and gas
rich protoplanetary disks provide key insights into the physics of star and
planet formation. When viewed edge-on, high resolution images offer a unique
opportunity to study both the radial and vertical structures of these disks and
relate this to vertical settling, radial drift, grain growth, and changes in
the midplane temperatures. In this work, we present multi-epoch HST and Keck
scattered light images, and an ALMA 1.3 mm continuum map for the remarkably
flat edge-on protoplanetary disk SSTC2DJ163131.2-242627, a young solar-type
star in $\rho$ Ophiuchus. We model the 0.8 $\mu$m and 1.3 mm images in separate
MCMC runs to investigate the geometry and dust properties of the disk using the
MCFOST radiative transfer code. In scattered light, we are sensitive to the
smaller dust grains in the surface layers of the disk, while the sub-millimeter
dust continuum observations probe larger grains closer to the disk midplane. An
MCMC run combining both datasets using a covariance-based log-likelihood
estimation was marginally successful, implying insufficient complexity in our
disk model. The disk is well characterized by a flared disk model with an
exponentially tapered outer edge viewed nearly edge-on, though some degree of
dust settling is required to reproduce the vertically thin profile and lack of
apparent flaring. A colder than expected disk midplane, evidence for dust
settling, and residual radial substructures all point to a more complex radial
density profile to be probed with future, higher resolution observations.
