Public participation in scientific research has been going on for decades and even centuries in some places. Recently there has been an explosion of interest as increasingly engaged citizens are eager to document their interactions with nature at the same time that conservation scientists are demanding real-time biological data at massive scales. While most programs focus on adult sightings, monarch scientists have pioneered engaging “super-volunteers” to collect more process-based data, such as tracking migration, juvenile development, and disease. We surveyed all monarch volunteer programs that collected data in 2011, quantified the amount of time volunteers invested in collecting data for each project, and integrated these values, stratified by spatial location (at a 1 degree resolution) and stage of the monarch’s annual cycle. Volunteers spent an estimated 86,000 hours in the field collecting data on monarchs in 2011; this is the equivalent of 40 full-time, year-round field workers. The majority of this time (70%) was spent on monitoring the fall migration, especially in the north central and eastern regions of North America. We also present a monitoring “gap analysis” that can be used to target future volunteer recruitment. Finally, we show that monitoring is leading to a more engaged citizenry, through volunteers who are participating in conservation and education activities and even presenting scientific results of their own research at national meetings.