Marla L. Demars, CFNP, CGNPCFNP, CGNPUnclaimed · claim itNurse Practitioner — GerontologyRapid City, SD20+ years experienceRegistered with an NPI since 2006. National Provider Identifiers only began in 2005, so a provider who qualified earlier may have practiced for longer than this.(605) 342-9788NPI 1760560957View Profile Claim