We report autodetachment spectra of the mass-selected, anionic water clusters, (H2O)(n)(-), n=2, 3, 5-9, 11 in the OH stretching region (3000-4000 cm(-1)), and interpret the spectra with the aid of ab initio calculations. For n greater than or equal to 5, the spectra are structured and are generally dominated by an intense doublet, split by about 100 cm(-1), which gradually shifts toward lower energy with increasing cluster size. This behavior indicates that the n=5 - 11 clusters share a common structural motif. The strong bands appear in the frequency region usually associated with single-donor vibrations of water molecules embedded in extended networks, and theoretical calculations indicate that the observed spectra are consistent with linear "chainlike'' (H2O)(n)(-) species. We test this assignment by recording the spectral pattern of the cooled (argon solvated) HDO . (D2O)(5)(-) isotopomer over the entire OH stretching frequency range.