St Mary's Medical Center

Faculty and Current Residents

View faculty biographies below and read about current resident students:

First Year
Second Year
Third Year 


facultydigioiaSabrina Mitchell, D.O., Program Director

Dr. Sabrina Mitchell was raised, skiing, in Mammoth Lakes, CA. She received her BS in Physiology from UCSD & graduated from University of New England, College of Osteopathic Medicine; residency was at MSU-Sparrow in Lansing, MI. She then headed for sunnier climates moving to Farmington, New Mexico where she worked in a community health center, opened a private practice & took on the job of Medical Director for Northwest New Mexico Hospice. Sabrina’s passions are hands on Osteopathic Manipulation, Palliative & End of Life care, & Non-Diet Weight Management. She is double boarded in Family Medicine and Hospice and Palliative Medicine. She has two daughters & enjoys riding her motorcycle, cooking, singing & teaching herself guitar. Her family is really enjoying all the great outdoor activities of the Grand Junction area.

facultydickersonKeith Dickerson, M.D.

Dr. Keith Dickerson was born and raised in Reading, PA. He received his BS in electrical engineering and MS in biomedical engineering from Drexel University in Philadelphia, PA but felt drawn to a career in medicine. He graduated cum laude and AOA from medical school at MCP in Philadelphia and completed his residency in Family Medicine at the University of New Mexico in Albuquerque. He then completed a four year Air Force commitment prior to joining St. Mary's in 2004. His current areas of professional focus are hospitalist/inpatient medicine, adult learning theory and practice, and graduate medical education optimization. He, his wife Teresa, and their daughter Sophia enjoy bicycling, hiking, Nordic and Alpine skiing, gardening, along with making music, in their spare time.

Taggart copyChristopher Taggart, M.D.

Dr. Chris Taggart was raised in Denver, CO and spent college, medical school, residency, and fellowship in Northeast Ohio. He received his BA in History from Case Western Reserve University and his MD from Northeast Ohio Medical University in Rootstown, OH. Residency and Hospice and Palliative Medicine fellowship were at Akron City Hospital in Akron, OH. After fellowship he worked at Rose FMR in Denver before following his wife to Rochester, NY. Where he was faculty for 4 years before joining us. He currently spends his free time with his family, especially enjoying watching his young son grow. He also likes to run, ski, hike, and travel on any adventure his wife plans. Monique Morisseau, M.D. Dr. Monique Morisseau comes to the residency with a strong commitment to the underserved. She grew up in Rhode Island, attending the University of New Hampshire for undergrad then Dartmouth Medical School & Brown’s Family Medicine Residency. Her initial practice was with the Indian Health Service in Northern Arizona working with the Hopi & Navajo. Monique especially enjoys teaching OB Ultrasound & connecting new residents with the wonders of the area. She has 2 daughters with her energetic Irish husband.

faculty_simmonsPaul Simmons, M.D., FAAFP

Dr. Paul Simmons is a Colorado native. After graduating with a degree in history from Baylor University, he attended the University of Colorado School of Medicine. His family medicine residency was completed in Greeley, Colorado, where he was elected chief resident. Dr. Simmons practiced family medicine including obstetrics, sleep medicine and endoscopy in rural areas of western Wisconsin and eastern Colorado, and was awarded the 2009 Rural Health Excellence Award by the Colorado Rural Health Center. Since moving to Grand Junction, he has not only taught family medicine residents, but also undergraduate biology students and graduate nursing students at Colorado Mesa University. His medical interests include physical examination, office procedures and evidence-based medicine. Dr. Simmons and wife, have three neurotic dogs and enjoy traveling, hiking and good food.


Andrew Gerdes, M.D.

Dr. Drew Gerdes is originally from Central Texas where he received his BA from the University of Texas at Austin and his MD from The University of Texas Medical School at Houston. He decided to look West for residency training and came to St. Mary's for residency because of the full-spectrum training, the incredible people, and the Rocky Mountains. He is thrilled to now be a part of the St. Mary's faculty where he enjoys practicing full-spectrum family medicine alongside our residents. Current areas of interest include pediatrics, inpatient medicine, and resident/physician wellness. When away from the residency, he can be found running, hiking, or skiing with his wife Shannon, planning his next international adventure, or camping in beautiful Western Colorado.

facultydavisaAmy Davis, M.D., MPH, AAHIVM

Dr. Amy Davis has been the medical director of the HIV Collaborative Clinic at SMFM since 2000. Her passion in medicine has been for special populations and the underserved. Her hometown is Queensbury, NY. She received her B.S. in biochemistry from Cornell University in Ithaca, NY then attended medical school at SUNY -Buffalo. She completed residency at Maine-Dartmouth FMR in August, Maine. She practiced 4 years with the Indian Health Service on the Hopi Reservation before joining the SMFM faculty. Her husband is an organic farmer. Together they have three children.


Lyrad Riley, MD

Dr Lyrad Riley grew up in a small town in Northern California. He attended Brigham Young University, then St Louis University Medical School. Residency was back in California at Travis AFB then fellowship in surgical obstetrics in Austin, TX. Dr Riley served as a Family Physician and Flight Surgeon in the Air Force for 20 years before joining St Mary's Family Medicine Residency. He has extensive International experience with over seven years throughout the world including: Great Britain, Germany, Slovenia, Haiti, Belize, Peru, Guam & 7 Nations in Africa. The last 6 years he was a faculty physician in Florida -- garnering several teacher of the year awards. His main areas of interest include travel medicine and maternity care.


Randall Reitz, Ph.D.

Dr. Randall Reitz is our Director of Behavioral Sciences. He received a PhD in Marriage and Family


 Therapy from Brigham Young University. He directs our Medical Family Therapy Fellowship and the integrated mental health team. His scholarly interests are professional identity development, trans-disciplinary training, and group medical appointments that he leads with our residents. Dr. Reitz speaks four languages (Spanish, French, Portuguese and English). Outside the clinic he is married, has three children, loves trail running, biking, and baking.





CMP_0483Edit2Karlynn Sievers, M.D.

Dr. Karlynn Sievers was born & raised in Kansas City. She majored in both English & Life Science @ the U of Missouri then off to med school at the Univ of Missouri at Columbia. She stayed in MO for her Family Medicine residency at Truman Medical Center. After completing her training Dr Sievers enjoyed a busy private practice in the small town of Rolla, MO. (pop 10,000) Then she decided to explore the world. New Zealand was the choice of an amazing place to practice for a season. The next step in her career was to teach the full spectrum family medicine she has been practicing - so she moved to the mountain west. She was "teacher of the year" at the University of WY - Casper, before joining the faculty in Grand Junction. She is married, has two boys, a parrot, & a bulldog. The majority of her time is spent with one of those five creatures, she also loves hiking, reading, and watching nerdy movies. Shall we discuss Star Trek vs Star Wars, & Harry Potter?

Olson copyMichael Olson, PhD, LMFT

Dr. Mike Olson comes to us from the University of Texas where he directed their behavioral medicine program for 11 years. Prior to that he worked at the University of Nebraska Medical Center in Omaha, NE, co-directing the behavioral medicine program and developing a medical family therapy Ph.D. program. He attended Brigham Young University for undergrad and his Masters degree in MFT, then Kansas State University for his Ph.D. and a post-doc fellowship in behavioral medicine from University of Texas. He is married - they have five children. Outside interests include music (piano), art, hiking, and Alpine skiing with the family.

Megan LykkeMegan Lykke, M.D.

Dr. Megan Lykke graduated from St Mary’s Residency, and after practicing in rural southern Colorado for 6 years, she liked it enough here to come back! She went to undergrad at Seattle Pacific University and then medical school at Michigan State University College of Human Medicine. She enjoys full-spectrum family medicine. Dr. Lykke loves mountain biking, hiking, and Nordic skiing the Colorado’s great outdoors with her husband and two boys

facultyreedersptsmedMike Reeder, DO, CAQ

Dr. Mike Reeder attended Ohio University med school. He completed an ER Residency at Akron General & his Fellowship at Albany Medical Center in NY. He moved here to work with the Residency, Colorado Mesa University & private practice. He's interested in all aspects of non- surgical orthopedics/sports medicine, exercise physiology, & biomechanics. He especially enjoys bicycling, cross-country skiing, & time with his family.

faculty_cookTonya Cook, Pharm.D.

  Dr. Tonya Cook is our pharmacy faculty. She earned her decorate of pharmacy at the University of New Mexico and then completed a residency in Ambulatory Care at the Asheville VA in North Carolina. Dr. Cook’s areas of interest include collaborative care, teaching, mental health, and pain management. Outside of work she enjoys reading, hiking and traveling.



Ryan Jackman, MD, Addiction Medicine

Dr. Ryan Jackman grew up in South Jordan, UT. Having completed his BA at Utah State University, his MD at The Medical College of Wisconsin, and residency in Grand Junction (finding a place that really felt like home) he moved again to complete a fellowship in Addiction Medicine at the University of Colorado in Denver. His research was funded by the National Institute on Drug Abuse & involved translational research in telehealth and resident education. Ryan elected to pursue family medicine because of his love for the breadth of medicine (also known as his inability to settle for just one specialty). Specific clinical interests include addiction medicine, obstetrics, and resident education. He was thrilled have the opportunity to return to St. Mary's and in the "Grand Junction way" build an integrated addiction medicine clinic within the family medicine residency. Outside of medicine he enjoys adventuring with his girls (wife and 3 children) whether that be hiking, camping, and playing princesses.



Katie Joy, DO

Dr. Katie Joy grew up in Alaska & Colorado & attended The University of Colorado, Boulder for her undergraduate degree in Kinesiology. Medical School was at Des Moines University School of Osteopathic Medicine & her Pediatric residency was at the University of New Mexico in Albuquerque. She joined Western Colorado Pediatric Associates in Grand Junction 4 years ago after working in Portland & Glenwood Springs & jumped at the chance to consistently work with residents. When she's not in the office you can find her enjoying the outdoors - everything Western Colorado can offer, biking, hiking, skiing, etc. - usually with her husband.

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