About Us

Rocky Mountain Family Medicine, LLC was established in February 2009 and opened for practice in Summer 2009. Rocky Mountain Family Medicine is a full-service family medicine practice caring for the primary care health needs for people of all ages in the Casper area.

Eric Lawrence, DO


Dr. Lawrence has been in Casper since 2006 and has been with Rocky Mountain Family Medicine since its inception. During the summers you may catch him hiking around Wyoming and the winters he enjoys nordic skiing since he moved to Casper from Texas where he grew up in the small Texas town of Farmersville, attended college in East Texas at Stephen F. Austin State University and medical school at the University of North Texas - Texas College of Osteopathic Medicine in Fort Worth.  He is board certified in Family Medicine and did his residency training in Casper at the University of Wyoming Family Medicine Residency.

Dr. Lawrence is a Doctor of Osteopathy, click for more information.

Dr. Lawrence’s CV (PDF Download)


RMFM Robyn

Robyn Morrison, PA-C was born and raised in Casper but spent much of her adulthood in Washington state and Colorado. She is grateful to return to her metown to practice medicine as a physician assistant.  Robyn graduated in 2016 from the University of Colorado Child Health Associate/Physician Assistant program.  Her training emphasized family medicine, rural healthcare and pediatrics.  Her professional interests include women’s health, chronic care management including diabetes and blood pressure, preventative care and nutrition.  She also performs minor procedures including Nexplanon implant, joint and trigger point injections, skin lesion removal/biopsy and toenail removal. Robyn enjoys working with patients of all ages.  She takes a patient-centered approach to build trust and develop relationships to work collaboratively with patients

Erica Costello, PA-C

RMFM Erica

Erica is the newest member of our team, starting in 2022 with Rocky Mountain Family Medicine, but originated in Casper 20 years ago, transplanting from California.  Erica has been a physician assistant since 2015 and completed her professional training at St. Francis University.  She enjoys pretty much anything outdoors, year round; you may find her out with her family camping, fishing, hiking, or cross-country skiing.  She is a board member and very active with the Wyoming Association of Physician Assistants.

At Rocky Mountain Family Medicine she spends most of her week caring for long term care patients at Shepherd of the Valley Nursing Facility to satisfy her interest in geriatrics, but also cares for her clinic patients through the office several days a week as well.  She continues honing her medical skills with her pursuit of certification as a diabetes educator and she enjoys dabbling in Functional Medicine.  Prior to her career in medicine she spent time working with the BLM studying the migratory path of birds and wind turbines.  We are excited to have Erica’s vibrant personality and years of experience caring for patients as a part of our team and we hope you get to meet her.  She is currently accepting new patients on a limited basis.