Early grunge concerts were sparsely attended (many by fewer than a dozen people) but Sub Pop photographer Charles Peterson's pictures helped create the impression that such concerts were major events. Mudhoney, which was formed by former members of Green River, served as the flagship band of Sub Pop during their entire time with the label and spearheaded the Seattle grunge movement. Other record labels in the Pacific Northwest that helped promote grunge included C/Z Records, Estrus Records, EMpTy Records and PopLlama Records.