Land managers depend on reliable natural resource information in the development and implementation of conservation strategies and in making decisions regarding resource use. Biological inventories are one of the most basic and important components of that information. The National Park Service (NPS) has undertaken a service-wide initiative to assess and monitor the condition of natural resources in its parks. To achieve this, the Service implemented an Inventory and Monitoring Program among networks of parks in similar settings. The Chihuahuan Desert Network (CHDN) that includes seven parks within this desert ecoregion developed its Inventory and Monitoring plan with network specific objectives.