350 Eastside is a child organization of 350.org, a left-of-center environmentalist organization that advocates for the elimination of carbon emissions and prohibiting the use of conventional fuels. It advocates for a transition to environmentalist energy through protests, lobbying, and monthly gatherings.
In August 2020, 350 Eastside, among others, petitioned for the removal of a weatherman Cliff Mass from a local news station because he allegedly minimized the “urgency of climate science,” eventually leading to him being fired.  Another local media outlet described the petition and complaints as an “orchestrated campaign” aimed at having Cliff’s commentary removed from the station. 350 Eastside was credited with using the petition to expand the “campaign” beyond individual complaints. 
In March 2020, 350 Eastside co-signed an open letter to Washington Governor Jay Inslee (D) that requests the immediate release of incarcerated individuals in response to the Covid-19 pandemic. The letter calls for the release of those who “do not pose a risk to public safety,” with short sentences, who were arrested for poverty violations, and to increase early release dates. 
Sara Holzknecht is a co-founder and the president of 350 Eastside. She has owned several businesses, volunteered for environmentalist groups, and worked for environmentalist groups as an organizer for political advocacy. 
Phillip Ritter is a co-founder and Steering Committee member of 350 Eastside. He is a financial consultant for nonprofit housing developers and incorporates feminist ideology with his environmental activism. 
350 Eastside is registered as a 501(c)(3) nonprofit organization. Its financial data is not publicly available as it reported less than $25,000 a year in gross receipts.