Colorado offers school choice through Open Enrollment allowing parents to enroll their children in schools other than those assigned by geographic boundaries. One side effect of open enrollment in Boulder County has been Stratification (think Segregation only by Choice instead of by legal mandate). Columbine is the most stratified elementary school in the City of Boulder and one of the most stratified in the County.
The Board commissioned a task force to study the stratification and make recommendations for remediation. Various related documents can be found here: BVSD Stratification Task Force archive 
. The Board also directed Columbine to attract more Caucasian families to the school. There's data in the Spreadsheet of Student Data Profiles for all Schools which helps illustrate why.
**Note**: We would like to include the data in the Spreadsheet of Student Data Profiles. The link provided appears to be broken and a search in the archive did not produce any results.
The Columbine data are pretty telling. In the 1997-98 school year, the school was 26% Latinos and 46% free/reduced lunch (a measure of family income). Those numbers increased quickly until 2004-05 when the school had 83% Latinos and 87% free/reduced lunch. The open enrollment data only go back to 2001-02. It peaked in 2002-03 with 64% of the kids in the attendance area open enrolling out of the school and has declined to about 58% open enrolling out. That last bit suggests that some of the changes they've made in the past five years have been helping to reduce the open enrollment, though it's probably not enough data to establish a trend.
Some other data not shown in the spreadsheet are as follows. The demographics of the attendance area right now are about 53% Latino and 38% Caucasian. 45% of the kids are English language learners and 87% free/reduced lunch.
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Volunteering at Columbine Elementary School (Race, Income, Stratification, Oh my!) blog
I (Eric Dobbs) reflect on many years of local activism and the jarring experience where I stopped. I now see it as a journey of growing awareness of racial and other identity and deep challenges to my idealism.
Some segregation results from the practices of organizations, some from specialized communication systems, some from correlation with a variable that is non‐random; and some results from the interplay of individual Choices. This is an abstract study of the interactive dynamics of discriminatory individual choices. One model is a simulation in which individual members of two recognizable groups distribute themselves in neighborhoods defined by reference to their own locations. A second model is analytic and deals with compartmented space. …