  We present the results of out-of-plane electrical transport measurements on
the heavy fermion superconductor CeCoIn$_{5}$ at temperatures from 40 mK to 400
K and in magnetic field up to 9 T. For $T <$ 10 K transport measurements show
that the zero-field resistivity $\rho_{c}$ changes linearly with temperature
and extrapolates nearly to zero at 0 K, indicative of non-Fermi-liquid (nFL)
behavior associated with a quantum critical point (QCP). The longitudinal
magnetoresistance (LMR) of CeCoIn$_{5}$ for fields applied parallel to the
c-axis is negative and scales as $B/(T+T^{*})$ between 50 and 100 K, revealing
the presence of a single-impurity Kondo energy scale $T^{*} \sim 2$ K.
Beginning at 16 K a small positive LMR feature is evident for fields less than
3 tesla that grows in magnitude with decreasing temperature. For higher fields
the LMR is negative and increases in magnitude with decreasing temperature.
This sizable negative magnetoresistance scales as $B{^2}/T$ from 2.6 K to
roughly 8 K, and it arises from an extrapolated residual resistivity that
becomes negative and grows quadratically with field in the nFL temperature
regime. Applying a magnetic field along the c-axis with B $>$ B$_{c2}$ restores
Fermi-liquid behavior in $\rho_{c}(T)$ at $T$ less than 130 mK. Analysis of the
$T{^2}$ resistivity coefficient's field-dependence suggests that the QCP in
CeCoIn$_{5}$ is located \emph{below} the upper critical field, inside the
superconducting phase. These data indicate that while high-$T$ c-axis transport
of CeCoIn$_{5}$ exhibits features typical for a heavy fermion system, low-$T$
transport is governed both by spin fluctuations associated with the QCP and
Kondo interactions that are influenced by the underlying complex electronic
structure intrinsic to the anisotropic CeCoIn$_{5}$ crystal structure.
