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Staff List


David Thayer, M.D.

Dr. Thayer moved to Boulder in 1985 and introduced the first and most successful obstetric practice with hospital-based certified nurse midwives. Several thousand babies later, he transitioned to focus solely on gynecology in 2000 and introduced minimally invasive surgical techniques to Boulder.

Dr. Thayer is a board-certified obstetrician and gynecologist, a Fellow of the American College of Obstetrics and Gynecology, a member of the Colorado Medical Society and the Boulder County Medical Society, and the Colorado Gynecologic and Obstetric Society. Dr. Thayer went to Grove City College in Grove City, PA for his undergraduate education, where he was elected Student Government President in his senior year. He graduated with his MD from Jefferson Medical College in Philadelphia, part of Thomas Jefferson Medical University.

He was the primary motivator in bringing the da Vinci robotic surgical system to Boulder and then performed the first robotic surgical procedure in Boulder County in 2007. He now focuses his energy and talent on helping women prevent health problems and ultimately avoid surgery. He specializes in evaluation and treatment of bleeding issues at any age, and unraveling and solving the hormonal mysteries that produce so many symptoms both before and after menopause. He speaks to public audiences on a variety of women's health topics.


Traci Shahan, WHNP-BC, Doctor of Nursing

Dr. Shahan is a board certified women's health nurse practitioner (WHNP-BC) and a clinical nurse specialist (CNS), both of which are Advanced Practice Nurse designations registered with the State of Colorado. She graduated cum laude with a Bachelor's Degree in Psychology, and earned her Doctorate in Clinical Nursing in 1998.

She regularly volunteers her skills as a WHNP both locally and globally, having traveled to Nepal to serve the Nepalese women. She is proficient in gynecology, first trimester obstetrics, gynecologic ultrasonography and reproductive endocrinology and infertility.


Charmaine Haravey - Practice Manager

Charmaine was hired in November 2013 as the Thayer Group prepared for the transition to Electronic Health Records (EHR) with Athena Health. Recognizing her organizational skills, she was offered the newly created position of Practice Manager in early 2014. She holds a bachelor's degree from University of California, San Diego and brings to the practice decades of experience in a variety of industries, including the health-care subset of disability case management.

Charmaine's broad knowledge and experience base in business, accounting, communications, technology and human resources management all come into play at the Thayer Group. With patient care the number one priority, she works to offer a compassionate and complete healthcare experience, from beginning to end.


Linda Caddell - Billing Specialist

Linda earned her Associates Degree in Medical Billing and Coding from IBMC and has been with The Thayer Group since September 2014. Previously, Linda was a Manager and Supervisor in retail sales. Linda's kind and patient nature allows her to provide answers and support to our patients with any billing needs. She finds that being with The Thayer Group gives her the opportunity to work alongside medical professionals, increasing her confidence in her career.


Manessa Ross - Medical Assistant

Manessa joined The Thayer Group initially as an extern with IBMC College's Medical Assisting program. Manessa has been in the medical field as a QMAP/Med Tech for over ten years focusing on elderly care. Manessa is excited to transition to women's health care and has always been fascinated by this speciality. Her caring and compassionate nature makes her a great part of our MA team.


Wendy Stark - Medical Assistant

Wendy graduated from Front Range Community College with an Associate Degree in Medical Assisting and a Certificate in Medical Administration. She has enjoyed her mid-life career change and working in an environment devoted to complete and quality women's healthcare.


Serenda Johnson - Medical Receptionist

Serenda is the newest member of our staff and brings 16 years of medical-related experience to the front desk. Most recently, she worked for six years in a busy six-provider Family Practice group down south. A native of Colorado Springs, she recently relocated to the Denver metro area, and looks forward to learning the nuances of women's healthcare here at The Thayer Group. Her kind and compassionate nature, and attention to detail, are an ideal fit for our patients. In her spare time, Serenda likes to read, hike with her dog and husband, and enjoy the many cultural activities this area has to offer.


Lindsey Kelly - Medical Receptionist

Lindsey joined the front desk team at The Thayer Group in November 2015. She earned her Medical Billing and Coding degree from IBMC in December 2013 and is getting her feet wet at the front before moving into more complicated territory. A native of Colorado, her sparkly personality is a great fit for our busy office. When she's not working, Lindsey enjoys hiking, camping and spending time with family.


Steph Welsh - Medical Receptionist

Steph came to The Thayer Group in November 2015 after completing the Medical Office Technology program at Front Range Community College and earning her MAA. Her mid-life career change choice was to work in women's healthcare, and she has enjoyed the challenging and fulfilling transition. Starting as an intern at The Thayer Group, we soon learned her enthusiasm was contagious, and couldn't let her leave. Every day she is learning new aspects of the medical field. In her spare time, Steph enjoys spending time at her mountain cabin and practicing karate - she's a black belt!!


Consulting Staff

Lois Willhour - Certified Ultrasound Technician

Lois brings specialized skill and experience to the Thayer Group for Women’s Care. She performs ultrasound exams in our office. She has been working in the specialty of obstetrics and gynecology, including infertility care, since 1986. Lois has been with the Thayer Group since 1993.

Not only is Lois an excellent ultrasound technician, she has other talents too. Lois is a skilled artist. She creates beautiful handmade quilts.