The NWSES is structured so that several competitions called regional science expos, held each year in February or March at sites around Oregon, send their top projects to a state level science competition, the Northwest Science Expo. Both regional fairs and NWSE send high school winners to the Regeneron International Science and Engineering Fair (ISEF).
High school students must qualify for NWSE by placing in the top one-third at their regional fair. Middle school students are invited to compete at NWSE without qualifying at a regional fair, but school limits apply. Middle school students are encouraged to attend a regional fair if it is available.
At NWSE high school students proceeding from regional fairs will compete for the top state awards and the chance to compete at Regeneron ISEF. The diagram below illustrates the relationships between the different regional fairs and the state fair.