Using community science to map western monarch butterflies (Danaus plexippus) in spring

This dataset contains user-submitted observations of monarch butterflies in the western United States (primarily California north of Santa Barbara) between February 14 and April 22 2020-2023. Observations were aggregated from iNaturalist, the Western Monarch Milkweed Mapper, and email submissions.The purpose of this study was to increase available data of monarch occurrences during this time period and gather information on potential breeding and habitat use during the first part of the spring migration.