EPR and ENDOR investigations are carried out on irradiated K₂SO₄ crystals doped with CrO₄²⁻ ions. They indicate the formation of CrO₄³⁻ centers interacting with a nearby proton. The identification of the CrO₄³⁻ centers is based on their g values, the orientation of the g tensor and the symmetry requirements. The results are compared with related studies on MnO₄²⁻ in K₂SO₄ and K₂CrO₄ hosts.