Pediatrics & Primary Care

Tonya Horn – ARNP. Tonya was born and raised in Iowa as an Oskaloosa native. She will begin serving patients at Mahaska Health as a Pediatric Nurse Practitioner after years of providing care for the community in our Emergency Room as an RN. Tonya started her nursing career in a Pediatric Intensive Care Unit and…

Walk-In Clinic

Heidi Powers, ARNP, joined the Mahaska Health Walk-In Clinic Care Team in February 2021. She is happy to be back home in this community, as her hometown is Barnes City, Iowa. Heidi earned her Master of Science in Nursing (Family Practice) through Clarkson College in Omaha, Nebraska, and is certified through the American Academy of…

Walk In Clinic, Pulmonology, Occupational & Employee Health

Arthur grew up in Illinois and spent the last 5 years as an intensive care unit nurse at Northwestern Memorial Hospital in Chicago. Arthur graduated with honors from DePaul University with a Master of Science in nursing and went on to earn his Advanced Registered Nurse Practitioner license from North Park University School of Nursing.…

Leah VanLoon ARNP Joins Primary Care Team

Family Practice & Walk-In Clinic

  Leah VanLoon, ARNP serves as a provider for the Walk-In and Primary Care clinics at Mahaska Health. VanLoon is from the Eddyville area and joined Mahaska Health with 16 years of prior nursing experience, most recently having worked as a Nursing Supervisor at ChildServe in Johnston, Iowa. She began her nursing education at Indian…

Jess Tokle

Family Practice

Family Nurse Practitioner Jessica Tokle decided to go into medicine because she enjoys helping patients and learning from them. Originally from Grinnell, Jessica is excited to be close to home again. During her first year of college, she discovered her passion for nursing and decided to obtain her masters in nursing. Jessica received her Family…

Anna Throckmorton, ARNP

Anna Throckmorton, ARNP began serving as a nurse practitioner at Mahaska Health in September 2019. For many patients, Anna will be a familiar face as she has been a part of the Mahaska Health family for the past 15 years serving in various capacities, most recently as a registered nurse in the Birthing Center. Anna,…

Tara Stout, DNP, ARNP

Family Practice

Tara Stout, DNP, ARNP joined Mahaska Health in December 2019 after receiving her Doctorate of Nursing Practice from Clarke University in Dubuque, Iowa. Many may know her as she spent some time at Mahaska Health during her clinical rotations with Dr. O’Brien and Tonya Johannes. Tara grew up in Sully, Iowa and lives on a…

Geriatric Care

Lisa Nelson, ARNP, provides Geriatric and Skilled Nursing care at Mahaska Health. For Lisa, she was led to providing geriatric care while she was completing her nurse practitioner degree at the University of Iowa in 2003. Her grandmother received care at a long-term care facility, and she realized quickly that she wanted to provide this…

Melissa Lamb, ARNP

Allergy/ Immunology/ Pulmonology

Melissa Lamb, ARNP specializes in the areas of allergy, immunology and pulmonology and has been with Mahaska Health since 2006. Lamb joined the team at Mahaska Health after 5 years of extensive pulmonary specialty experience at Mayo Clinic in Rochester, Minnesota. Melissa can empathize with patients because she has been on the patient side of…

Gayle Johnson, ARNP

Family Practice

Gayle Johnson, ARNP joined Mahaska Health in November 2019. For more than 30 years, Gayle has been a caring nurse in Grinnell, Iowa. During her tenure there, she has worked in the Medical Surgical Unit as a charge nurse and served as clinical advisor for the medical surgical unit, intensive care unit, emergency department, and…