The iodine gas cell is replaced by the telluric O2 and water vapor lines to calibrate observations of RV stable M dwarfs made with the High Resolution Spectrograph of the Hobby-Eberly Telescope. Radial velocities are to be measured with both iodine lines in the visible and the atmospheric lines in the 6000-8800A region, as a first step in determining the utility of telluric lines as R-band radial velocity calibrators. Based on other published results, we expect that by modeling atmospheric effects in sufficient detail, a precision of <10 m s-1 is attainable. If feasible, this method will be used to search for Neptune-mass planets around K and M dwarfs.