  We propose an optical analogue of electron snake states based on artificial
gauge magnetic field in photonic graphene with effective strain implemented by
varying distance between pillars. We develop an intuitive and exhaustive
continuous model based on tight-binding approximation and compare it with
numerical simulations of a realistic photonic structure. The allowed lateral
propagation direction is shown to be strongly coupled to the valley degree of
freedom and the proposed photonic structure may be used a valley filter.
