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The southwestern willow flycatcher (Empidonax traillii extimus) is an endangered subspecies of willow flycatcher that occupies dense riparian habitats of the southwestern United States.� Many factors, including improper livestock grazing practices, are thought to explain declines in this species, although no long�term studies have sought to quantify the effects of grazing on willow flycatcher habitat.� The main goal of our study was to determine how time�controlled grazing by domestic livestock effects willow flycatcher habitat in west�central Arizona by: 1) measuring key vegetation attributes before and after livestock grazing, and at the end of the growing season; 2) providing quantitative baseline data on riparian woody vegetation that are considered vital habitat characteristics; and 3) assessing the effects of episodic rainfall events throughout the year.� We monitored vegetation on two ranches along the same watershed in west�central Arizona throughout 2015 and 2016, and focused on changes in vegetation in response to routine livestock grazing practices.� Specifically, we monitored mean utilization (%) of woody and herbaceous plant species; biomass (%), cover (%), and height (m) of the dominant plant species (woody and herbaceous); and density (#/m2) of woody plant species (seedlings).� Time�controlled livestock grazing (< 62 days) resulted in low relative and total utilizations (< 14%) for both herbaceous and woody plants during all sampling periods.� Consequently, species composition, canopy cover, and woody height of non�seedling woody plants remained relatively stable across most sampling periods.� Density of woody seedlings changed most in response to episodic flooding.��