How far are you willing to go? If you must, your best bet is the Indian reservation.
Do be aware of the penalties:
“FIREWORKS – KEEP IT SAFE! KEEP IT CLEAN!
LEGAL DISCHARGE DATES & TIMES: Legal fireworks may be used from noon to 11 p.m. on June 28, and from 9 a.m. to 11 p.m. through July 5. (On July 4 only, fireworks may be used until midnight.) It is illegal to discharge fireworks at all other times. Fireworks may not be used in public parks or on school properties.
FINES: In the City of Vancouver the fine for a single violation for unlawful sale, use or possession of legal fireworks is $250, or $500 for illegal fireworks. (There may be additional civil or criminal consequences for injuries or fires caused by irresponsible use.) Outside Vancouver city limits, the Clark County Fire Marshal and other local law enforcement agencies have the authority to cite violators.”