Saturation-dip measurements for the ${\mathrm{\nu }}_8\mathrm{C}–\mathrm{O}$ stretching band of ${\mathrm{CH}}_3\mathrm{OH}$ have been systematically carried out with a ${\mathrm{CO}}_2$ -laser–microwave-sideband spectrometer operating on low- and high- $J9.6\mathrm{\mu }\mathrm{m}$ P-branch ${\mathrm{CO}}_2$ laser lines. Frequencies of nearly 500 spectral lines, including overlapped and doublet lines unresolved in dense Doppler-limited spectra, have been measured with a resolution of $0.4\mathrm{MHz}$ and absolute accuracy of the order of $\pm 100\mathrm{kHz}$ . Over 200 frequency combination loops have been formed from the present and previous sub-Doppler observations, unambiguously confirming the infrared transition assignments, and refined term values have been determined for 623 excited vibrational levels. These results constitute a substantial database of high-accuracy frequency reference standards for ${\mathrm{CH}}_3\mathrm{OH}$ in the $10\mathrm{\mu }\mathrm{m}$ region, with applications in frequency calibration, in detailed studies of the complicated methanol intermode vibrational interactions, and in the interpretation of optically pumped far-infrared laser emission.