Sexual relations which occur between adults and teenagers under 18 are left in a legal gray area: laws against corruption of minors as well as estupro laws can be applied to such acts, at the discretion of the prosecution.
Typically, Mexican states have a "primary" age of consent (which may be as low as 12), and sexual conduct with persons below that age is always illegal.
Persons below the age of consent may not, by law, give consent, and sexual relations involving such persons may be punished by criminal sanctions similar to those for rape or sexual assault.
If minors are caught driving with even a .02 blood alcohol level, they are likely to lose their license for up to three months.
For more details about Minor in Possession charges (they can also result from minors having firearms or drugs), see the Department of Licensing website.
The only legal circumstances were a person under 21 can drink in Washington is in a private residence in the presence of their parent or guardian or for a religious ceremony such as Roman Catholic communion.
Marijuana is legal for recreational use in Washington State and most of the rules for alcohol apply to this substance as well.
In fact, when weed became legal in 2012, it was the Washington State Liquor Board that took over the laws for marijuana as well.