Species in alpine systems are known to be affected by climate change due to phenological shifts. MeadoWatch is a community science project with over 500 volunteers participating to date that has been gathering data on the timing of key reproductive phenophases (budding, flowering, fruiting, and seeding) at Mt Rainier National Park (WA, USA) since 2013. Volunteer observations of alpine meadow flowering phenologies at the park have led to numerous insights into climate change impacts on flowers and visitors. For example, our studies have illustrated that climate change will fundamentally alter the timing, composition, and diversity of the Alpine wildflower season, with potential consequences both for the ecosystem and the relationship of visitors with the National Park. Overall, the MeadoWatch program demonstrates that community science, crowd-sourcing, and remote sensing can be profitably combined with more traditional observational approaches to quantifying phenology for maximal insight.