Needs more secondary sources
A biography by the leader's brother and materials from the center are not sufficient to tell this account. Given the state and national attention the events commanded, and their relation to other major actions by Indians, there must be many articles by mainstream press of the time, and academic studies later. Other sources and points of view should be cited.    

History
This section should provide more context - e.g., number of Indians in Seattle compared to general population, nature of urbanized Indians (what brought them to Seattle? and when?), issues that they faced in employment, discrimination, etc. What else were their groups doing? It mentions the Alcatraz occupation but not much context for that, either. How many people were in the local activist group when they started? How many were arrested?  

Center operations
It would be useful if more information were provided about the operations and their effects: important art shows, # of visitors annually, outreach to Indian and other children, etc.