We present the ferromagnetism and magnetotransport properties in the (Ga,Mn)N epitaxial films with very low Mn concentrations grown by plasma-enhanced molecular beam epitaxy (PEMBE). The (Ga,Mn)N epitaxial films were found to exhibit ferromagnetic ordering with Curie temperature of 700 K. All the films exhibit n-type characteristics. The negative magnetoresistance was observed below 150 K, and found to gradually increase with decreasing temperature. The ferromagnetism in the (Ga,Mn)N is due to the Rudennan-Kittel-Kasuya-Yosida (RKKY) interaction between the localized Mn moments mediated by the electron gas.