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abstract: 'We report the results of a 100 square degree survey of the Taurus Molecular Cloud region in the J = 1 $\rightarrow$ 0 transition of  and of . The image of the cloud in each velocity channel includes $\simeq$ 3$\times$10$^6$ Nyquist-—sampled pixels, sampled on a 20grid. The high sensitivity and large linear dynamic range of the maps in both isotopologues reveal a very complex, highly structured cloud morphology. There are large scale correlated structures evident in  emission having very fine dimensions, including filaments, cavities, and rings. The  emission shows a quite different structure, with particularly complex interfaces between regions of greater and smaller column density defining the boundaries of the largest–scale cloud structures. The axes of the striations seen in the  emission from relatively diffuse gas are aligned with the direction of the magnetic field. We have developed a statistical method for analyzing the pixels in which  but not  is detected, which allows us to determine the CO column in the diffuse portion of the cloud as well as in the denser regions in which we detect both isotopologues. Using a column density–dependent model for the CO fractional abundance, we derive the mass of the region mapped to 