Although many studies have used information at the school level to measure the degree of racial segregation between schools, the absence of more detailed data has limited the analysis of segregation within schools. Using a rich set of administrative data on North Carolina public schools, this paper examines patterns of enrollment both across and within schools, allowing researchers to assess the comparative importance of segregation of each type and how they interact. To examine patterns in upper as well as lower grades, researchers perform separate tabulations for 1st, 4th, 7th, and 10th grades. The data make possible what they believe to be the most comprehensive study of within-school segregation undertaken in two decades, one that covers schools in all 117 districts of a large and racially diverse state. Using data for 1994-1995 and 2000-2001, they find marked increases in segregation over the period. In addition, they find that within-school segregation was much less important in the elementary grades than in 7th and 10th grades and that segregation of both types tended to be greatest in districts with nonwhite shares between 50 and 70 percent. Graphs and tables are appended. (Contains 27 references.) (Author/SM)