Higher order terahertz Stokes beams generated at 13 terahertz wavelengths in the 1-2 THz range was achieved with an injection-seeded THz -wave parametric generator (is-TPG) via a cascaded process within a nonlinear optical crystal. The injection beams from two external cavity diode lasers serve as both the pump and seed beams and generated more than 6-fold the number of terahertz wavelengths. Intensity variations that were observed may be explained by distributions of parametric gain, crystal entry positions and mirror alignment. The dynamic range exceeded 55 dB and the stability was about 5%. Practical applications such as reagent identification are possible with this real-time spectroscopy technique.