California's ~129 million standing dead trees have altered fire risk near rural communities and spurred policy changes to incentivize woody biomass energy. Details on the biomass of recently dead trees can be helpful for informing strategies to mitigate the tree mortality crisis. UC Berkeley researchers have combined data from the Forest Service with forest structure models to map dead tree biomass across the state. With help from UCANR's IGIS team, we have created a web tool that allows anyone to view and download tree mortality information for anywhere in California. This webinar will briefly explain the methods powering the web tool and then demonstrate how it can be used and how its results should be interpreted. Afterwards, there will be the option to sign up for small group video conference or in-person help sessions to go over more specific tasks. Feel free to access the web tool ahead of the webinar at http://geodata.ucanr.edu/biomass/.