Thomas Addison is a primary care provider, practicing in Geriatrics and Internal Medicine in Great Falls, Montana. Dr. Addison is rated as an Experienced provider by MediFind in the treatment of Retinopathy Arteriosclerotic. His top areas of expertise are Idiopathic Edema, Generalized Tonic-Clonic Seizure, Trichohepatoenteric Syndrome, and Anemia. Dr. Addison is currently accepting new patients.

Lyle Onstad is a primary care provider, practicing in Family Medicine in Great Falls, Montana. Dr. Onstad is rated as an Experienced provider by MediFind in the treatment of Retinopathy Arteriosclerotic. His top areas of expertise are High Cholesterol, Benign Paroxysmal Positional Vertigo, Anemia, and Chronic Obstructive Pulmonary Disease (COPD). Dr. Onstad is currently accepting new patients.

James Legan is a primary care provider, practicing in Internal Medicine in Great Falls, Montana. Dr. Legan is rated as an Experienced provider by MediFind in the treatment of Retinopathy Arteriosclerotic. His top areas of expertise are Lung Metastases, Hypertension, Glucocorticoid-Remediable Aldosteronism, and Familial Hypertension. Dr. Legan is currently accepting new patients.

Daniel Gordon is a primary care provider, practicing in Family Medicine in Great Falls, Montana. Dr. Gordon is rated as an Experienced provider by MediFind in the treatment of Retinopathy Arteriosclerotic. His top areas of expertise are Lung Cancer, Alzheimer's Disease, Orthostatic Hypotension, and Relapsing Multiple Sclerosis (RMS). Dr. Gordon is currently accepting new patients.

Anna Earl is a primary care provider, practicing in Family Medicine in Great Falls, Montana. Dr. Earl is rated as an Experienced provider by MediFind in the treatment of Retinopathy Arteriosclerotic. Her top areas of expertise are Nephrosclerosis, Renovascular Hypertension, Hypothyroidism, and Postmenopausal Osteoporosis.

Mark Morasch is a Vascular Surgeon in Great Falls, Montana. Dr. Morasch is rated as an Experienced provider by MediFind in the treatment of Retinopathy Arteriosclerotic. His top areas of expertise are Thoracic Aortic Aneurysm, Carotid Artery Disease, Abdominal Aortic Aneurysm (AAA), Carotid Artery Surgery, and Aneurysm Repair. Dr. Morasch is currently accepting new patients.

Dr. Brett Williams was born and raised in Comanche, Oklahoma, a small town in southern Oklahoma where almost everyone made their living by farming, ranching or in the oil industry. He graduated from the University of Oklahoma in l978 with a Bachelor of Arts Degree, majoring in Psychology. He graduated from medical school at the University of Oklahoma Health Science Center in l982 and completed his general surgery residency at Cornell University in 1987 and his cardiovascular and thoracic surgical fellowship at State University of New York in Brooklyn in l990. After graduation, he had multiple opportunities to join practices in large metropolitan areas as well as university settings. However, he was intrigued by the “Last Best Place” and ultimately decided to establish his practice in Cardiovascular and Thoracic surgery in Great Falls, Montana in September 1990. He has provided continuous coverage in these specialties since that time. During those 28 years, Dr. Williams has championed innovations in surgical technique and technology to be able to provide state of the art care with surgical outcomes that consistently lead the region and the nation. Some of the innovations that were introduced by Dr. Williams to Central Montana include off pump coronary artery bypass grafting procedures, complex mitral valve repair, complex aortic root reconstruction and valve preservation, transmyocardial laser revascularization of the heart, minimally invasive valve surgery, minimally invasive coronary artery revascularization, surgical correction of atrial fibrillation, minimally invasive vascular surgery, minimally invasive thoracic surgery. He was one of the first surgeons to provide outpatient treatment with endovascular laser therapy for varicose veins. Dr. Williams is Board Certified by the American Board of Thoracic Surgery. A Fellow of the American College of Surgeons and a member of the Society of Thoracic Surgeons. Dr. Williams is rated as an Advanced provider by MediFind in the treatment of Retinopathy Arteriosclerotic. His top areas of expertise are Carotid Artery Disease, Thoracic Aortic Aneurysm, Abdominal Aortic Aneurysm (AAA), Carotid Artery Surgery, and Heart Bypass Surgery.

Dr. Jorge (pronounced “George”) Castriz is a board certified interventional cardiologist. Dr. Castriz offers the full complement of cardiology services including arterial catheterization, biventricular pacing, temporary pacemakers, conventional and stress echocardiography as well as exercise and pharmacologic stress testing. He also brings his expertise in all aspects of peripheral angiography and coronary angioplasty (AAA endovascular stent grafts, renal artery stents, angioplasty, DCA, rotablator, brachytherapy, IVUS and physiologic lesion assessment). Dr. Castriz is board certified in Internal Medicine, Cardiovascular Diseases and Interventional Cardiology and is a fellow of the American College of Cardiology. Prior to joining the Great Falls Clinic in 2013, Dr. Castriz maintained an active practice with the Cardiovascular Medical Specialists of the Palm Beaches in Jupiter, Florida. Prior to that, Dr. Castriz owned a private practice in Palm Beach Gardens, Florida for nine years. Dr. Castriz received his medical degree from the University Central Del Este in the Dominican Republic. He completed his internship and residency in Internal Medicine, and his fellowship in Interventional Cardiology at the University of Oklahoma Health Science Center in Oklahoma City, OK. Dr. Castriz is rated as an Experienced provider by MediFind in the treatment of Retinopathy Arteriosclerotic. His top areas of expertise are Angina, Coronary Heart Disease, Heart Attack, Metabolic Syndrome, and Pacemaker Implantation.

Dr. Ritchie offers the full complement of cardiology services including arterial catheterization; temporary pacemakers; conventional and stress echocardiography, transesophageal echocardiography as well as exercise and pharmacologic stress testing. He also brings his expertise in all aspects of coronary angioplasty, including structural heart disease such as closure of atrial septal defects, balloon valvuloplasties; and peripheral angiography (AAA endovascular stent grafts, renal artery stents), DCA, rotablator, brachytherapy, IVUS and physiologic lesion assessment. Dr. Ritchie is board certified in Internal Medicine, Cardiovascular Diseases and Interventional Cardiology. Dr. Ritchie completed his undergraduate work at the University of Evansville, where he played baseball for three years. He attended medical school at Indiana University, where he graduated with highest honors in 1986. He then went on to complete his residency at Case Western Reserve School of Medicine in Cleveland in 1989. From there, he went on to complete his fellowship at Washington University in Saint Louis, where he performed clinical rotations while receiving interventional training. In his spare time Dr. Ritchie enjoys hiking, fishing, hunting, biking and spending time with friends and family. Dr. Ritchie is rated as an Experienced provider by MediFind in the treatment of Retinopathy Arteriosclerotic. His top areas of expertise are Atrial Septal Defect (ASD), Patent Foramen Ovale, Unstable Angina, Carotid Artery Disease, and Pacemaker Implantation.