  In order to constrain the evolutionary history of the Milky Way, we hunt for
faint RR Lyrae stars (RRLs) using Dark Energy Camera data from the High cadence
Transient Survey (HiTS) and the Halo Outskirts With Variable Stars (HOWVAST)
survey. We report the detection of $\sim500$ RRLs, including previously
identified stars and $\sim90$ RRLs not yet reported. We identify 9 new RRLs
beyond $100$ kpc from the Sun, most of which are classified as fundamental-mode
pulsators. The periods and amplitudes of the distant RRLs do not place them in
either one of the two classical Oosterhoff groups, but in the Oosterhoff
intermediate region. We detect two groups of clumped distant RRLs with similar
distances and equatorial coordinates, which we interpret as an indication of
their association with undiscovered bound or unbound satellites. We study the
halo density profile using spheroidal and ellipsoidal ($q=0.7$) models,
following a Markov chain Monte Carlo methodology. For a spheroidal halo, our
derived radial profile is consistent with a broken power-law with a break at
$18.1^{+2.1}_{-1.1}$ kpc separating the inner and the outer halo, and an outer
slope of $-4.47^{+0.11}_{-0.18}$. For an ellipsoidal halo, the break is located
at $24.3^{+2.6}_{-3.2}$ kpc and the outer slope is $-4.57^{+0.17}_{-0.25}$. The
break in the density profile is a feature visible in different directions of
the halo. The similarity of these radial distributions with previous values
reported in the literature seems to depend on the regions of the sky surveyed
(direction and total area) and halo tracer used. Our findings are compatible
with simulations and observations that predict that the outer regions of Milky
Way-like galaxies are mainly composed of accreted material.
