Bees and other pollinators play an essential role in maintaining the plant biodiversity of our planet's landscape through pollination. Few baseline studies or monitoring programs have addressed concerns over local, regional and even worldwide declines in bee populations. We established 22 collection sites in meadow and grassland habitats in Marin County, California to determine which bee genera were present and which plants they were visiting. Some of these habitats were located in National Park Service natural areas and wildlands, including Golden Gate National Recreation Area and Point Reyes National Seashore. During this study we collected a total of 109 bee, wasp and fly specimens and from among these we identified seven genera of bees. The bees were found on 44 species of plants, only 11 of which were native to Marin County. The European honey bee (Apis mellifera), a non-native pollinator, was found on 37 species of plants, 28 of which were non-native.