  We have studied spin transport and magnetoresistance in yttrium iron garnet
(YIG)/NiO/Pt trilayers with varied NiO thickness. To characterize the spin
transport through NiO we excite ferromagnetic resonance in YIG with a microwave
frequency magnetic field and detect the voltage associated with the inverse
spin-Hall effect (ISHE) in the Pt layer. The ISHE signal is found to decay
exponentially with the NiO thickness with a characteristic decay length of 3.9
nm. This is contrasted with the magnetoresistance in these same structures. The
symmetry of the magnetoresistive response is consistent with spin-Hall
magnetoresistance (SMR). However, in contrast to the ISHE response, as the NiO
thickness increases the SMR signal goes towards zero abruptly at a NiO
thickness of $\simeq$ 4 nm, highlighting the different length scales associated
with the spin-transport in NiO and SMR in such trilayers.
