  We report transport measurement in zero and applied magnetic field on a
single crystal of NbAs. Transverse and longitudinal magnetoresistance in the
plane of this tetragonal structure does not saturate up to 9 T. In the
transverse configuration ($H \parallel c$, $I \perp c$) it is 230,000 \% at 2
K. The Hall coefficient changes sign from hole-like at room temperature to
electron-like below $\sim$ 150 K. The electron carrier density and mobility
calculated at 2 K based on a single band approximation are 1.8 x 10$^{19}$
cm$^{-3}$ and 3.5 x 10$^{5}$ cm$^2$/Vs, respectively. These values are similar
to reported values for TaAs and NbP, and further emphasize that this class of
noncentrosymmetric, transition-metal monopnictides is a promising family to
explore the properties of Weyl semimetals and the consequences of their novel
electronic structure.
