Cool Stars 14 - Submitted Abstract # 42 This version created on 05 October 2006 SDSS/Johnson-Cousins/2MASS Color Transformations for Cool Stars James Davenport, University of Washington Andrew West, Berkeley. The SDSS and 2MASS have been rich sources for identifying and studying late-type stars. Because of the scale of these surveys it is important to have well defined calibrations such as parallax relations and color transformations to older photometric systems. Using the 0.78m MRO telescope, we observed Johnson-Cousins VRI and SDSS riz colors and magnitudes for 23 faint stars in the SDSS footprint, as well as 17 stars outside of the footprint with measured trig parallaxes. Combining these observations with SDSS, 2MASS and PMSU survey data, we provide extended color transformations and parallax relations for late type stars. ----------------------------------