(Salem, OR)  --  Oregon's new mask mandate takes effect tomorrow.  All residents will be required to wear a mask in public indoor settings regardless of COVID-19 vaccination status.  Governor Kate Brown issued the mandate earlier this week due to rising case numbers being caused by the highly contagious Delta variant of COVID-19.  Health officials say the Delta variant is causing COVID-19 cases to rise to their highest level so far during the pandemic, and masks are the fastest way to reduce the trend.