Status: Legal for recreational use

Policy History:

1923: Washington State legislature passes the bill to criminalise marijuana, punishable by up to 10 years in prison
1971: No longer a crime to possess up to 1.4oz (40g) of marijuana
1998: Initiative 692 Referendum results in the legalisation of medical marijuana
2012: Recreational cannabis is made legal 

Policy Framework:

Consumers:

• Must be above the age of 21 to purchase, possess or consume cannabis;
• May not consume cannabis in public places;
• May not drive under the influence of cannabis;
• An excise tax of 37%;
• May not consume cannabis in public view.

Suppliers:

• Must be state-licensed;
• Can’t sell more than 1oz (30g) to an individual in a single transaction;
• People are not permitted to cultivate their own cannabis (punishable by $US10,000 fine).

Outcomes:

• Youth use rates declined, according to a Centres for Disease Control (CDC) study;
• The 2019 Liquor and Cannabis Board report showed the cannabis industry in Washington generated $US367.4 million in 2018 and $US395.5 million in 2019;
• Adult use rates slightly increase;
• Percentage of traffic fatalities in which the driver tested positive for recent marijuana use rose from 12.8% in 2010 to 22.2% in 2014;
• Violent crimes and property crimes all decreased from 10%-30% after legalisation in Washington.

Source: https://crime-data-explorer.fr.cloud.gov/explorer/state/washington/crime