A search for California LIDAR brought up a NASA Planetary Geodynamics Laboratory link with some very localized LIDAR geotiffs. I recognized the name Fort Ross, so downloaded these images, and they’re great. There are four files for each area, a digital elevation model (DEM) with tree heights, a DEM without tree heights, and hillshades of each DEM. I thought about how I could call out forested areas, and came to the conclusion that I could subtract the DEM without trees from the DEM with trees to just get heights of objects above the ground. The biggest differences, the highest trees, are shown as dark green, the smaller differences are shown as yellowish grasses and shrubs, and no difference is shown as blue water. Set transparencies between this layer and both hillshades, and we get a pretty great land cover map. Click on the image below to see a high resolution version, and further below you will see the DEMs and calculation described above.
