Located on San Francisco's Treasure Island, Walden House Residential Stepdown Mariner is one of three stepdown facilities operated by HealthRIGHT 360 as part of their broader Walden House program. This residential facility provides supportive housing for individuals who are actively participating in outpatient treatment for substance use disorders or mental health conditions, whether through HealthRIGHT 360's extensive network or external programs. The Mariner location primarily serves vulnerable populations including those experiencing homelessness, justice-involved individuals, LGBTQ+ community members, young adults, people with a history of injection drug use, and those living with HIV/AIDS. While this particular program follows an abstinence-based approach to recovery, it's worth noting that HealthRIGHT 360 offers alternative programs utilizing harm reduction models. As part of HealthRIGHT 360's comprehensive system of care spanning 50 programs across 11 California counties, Walden House Residential Stepdown Mariner represents an important transitional housing option that bridges the gap between intensive treatment and independent living for those working toward long-term recovery and stability.