$\mu$m. A weak unresolved Na I doublet is seen at 1.26826 $\mu$m in order 60. The first pair of strong K I lines at 1.24357 and 1.25256 $\mu$m appears in order 61. Multiple weak absorption features occur in both orders 62 and 63, the most notable grouping being the set of lines around 1.222 $\mu$m. Several of the stronger features have been identified with FeH from lower resolution studies (Jones et al. 1996; Cushing et al. 2003; M03). Note however, that a major FeH band head at 1.24 $\mu$m is just off the detector at the short wavelength edge of this order. In order 64 there is a pair of strong Fe I lines at 1.18861 and 1.18873 $\mu$m and another Fe I line at 1.19763 $\mu$m. Order 65 contains the second set of strong K I lines, one at 1.169342 $\mu$m and the close pair at 1.177286, 1.177606 $\mu$m. In general, the lines are relatively sharp and well-resolved. Wolf 359 is a bright source and therefore the signal-to-noise ratio in this spectrum is at least 100:1.

Following these spectral features order by order through Figures 1-6 reveals certain general trends as a function of spectral type. Comparing the M9 