Seven reflectance spectra of Umbriel. All 15 spectra (A2, A3) were normalized to unity between 1.74 and 1.77 μm. These spectra were smoothed using the boxcar function described in the caption of Figure 1 (black), along with the 1σ uncertainties shown at their native resolutions (gray). The mid-observation subobserver longitude is listed in the top left corner of each plot. Relevant observing information for each spectrum is summarized in Table 1, organized by subobserver longitude. The greater point-to-point variation and lower S/N between 1.08 and 1.14 μm, 1.31 and 1.46 μm, 1.78 and 1.96 μm, and ≳2.35 μm results from increased telluric absorption in these wavelength regions. The sensitivities of SpeX (SXD mode) and TripleSpec are lower at wavelengths <1.4 μm and >2.3 μm, further reducing the S/N beyond these wavelengths. Additional structure at wavelengths <1.3 μm in some of the spectra results from scattered-light contributions from Uranus.