About Us In Milwaukee, WI, Ascension Columbia St. Mary’s Hospital Milwaukee and ER is a tertiary care hospital with advanced specialty care services. Ascension Columbia St. Mary’s Hospital Milwaukee in Milwaukee, Wisconsin delivers tertiary specialty and 24/7 emergency care and walk-in appointments at our Urgent Care clinic. We provide advanced surgical care for serious and life-threatening injuries and illnesses. Our care teams listen to understand your health needs and deliver care that's right for you. Ascension Columbia St. Mary’s Milwaukee is a destination for specialty care - including heart and vascular health, cancer care, stroke care, orthopedics and women’s health. Our OB-GYN maternity care teams at our Birthing Center deliver a personalized birthing experience. We offer a wide range of minimally invasive procedures using robotic-assisted technology, imaging and lab tests, a dedicated inpatient rehabilitation center, all on one campus.