This study identifies several trends related to the performance of Colorado charter schools. In the 1998-99 school year, their performance as a whole on the Colorado Student Assessment Program was stronger than state averages, stronger than sponsoring district averages, and stronger than the average performance of other public schools in the same socioeconomic classification level. The great majority of charter schools were meeting--or exceeding--the performance goals they identified in their individual charter applications and in subsequent school-improvement plans. The market indicators--waiting lists, retention rates, and parent satisfaction--were, as a whole, positive. These charter schools were diverse in size, educational programs, educational philosophies, approach to governance, and assessment strategies. Finally, as a group, the schools were demonstrating increased maturity to measure, track, and report student and school performance data. Appendices list the Colorado Charter Schools Act and supply questionnaire and school profile/data forms. (DFR)