CREATE TABLE table_30026 ("Year" FLOAT, "Location" CLOB, "Distance  ( miles ) " FLOAT, "Rider Names" CLOB, "Horse Name" CLOB, "Best-Conditioned Horse" CLOB)

Who were the winning riders of the championship in Euer Valley, CA and whose horse was Magic Sirocco?
SELECT "Rider Names" FROM table_30026 WHERE "Location" = 'Euer Valley, CA' AND "Horse Name" = 'Magic Sirocco'
SELECT "Rider Names" FROM "table_30026" WHERE "Horse Name" = 'Magic Sirocco' AND "Location" = 'Euer Valley, CA'