Federal cropland retirement programs are increasingly being used to provide resources for pollinators (e.g., nectar, pollen, host plants). Pollinator-friendly plant species (e.g., alfalfa, sweetclover) were readily included in seed mixes in Conservation Reserve Program (CRP) grasslands since its inception in the 1985 Farm Bill. Through time, some native plant species (e.g., milkweeds) also colonized CRP grasslands. Since the mid 1990s, Northern Prairie has been quantifying changes in pollinator resources (alfalfa, sweetclover, and milkweed) and monarch butterfly abundance in several hundred CRP grasslands in nine counties in the northern Great Plains. Understanding the long-term persistence, increase, or decline of monarchs and pollinator resources in CRP grasslands will help inform the design and management of current and future long-term cropland retirement programs.