The project includes vehicle and heavy equipment use within the riparian corridor and bank full channel of the Mad, Lower Eel, Van Duzen, and Trinity rivers, excavation of aggregate from exposed bar surfaces, excavation of aggregate from deposits adjacent to the low-flow summer stream channel, isolated water bodies, and secondary channels. Access to extraction site amy require the placement and removal of temporary crossings. Excavation may also occur on high floodplain areas and in areas adjacent to riparian vegetation. The annual work period occurs between June 1 and October 15, with the exception of temporary crossings, which are restricted to the work period of June 30 and October 15. Pre-extraction monitoring and planning activities begin as early as April 1 and may extend through July. Post-extraction monitoring and habitat surveys may extend through the month of November. Pre-extraction planning activities may involve travel to survey areas by passenger vehicle on existing haul roads and across exposed gravel bars of the Mad, Eel, Van Duzen river channels. Equipment used for excavation activities include rubber-tired loaders, tracked bulldozers, belly-scrapers, tracked excavators, large off-road haul trucks, belly dumps, dump trucks, personal vehicles, and quad runners.