I worked for NPS in Yosemite, many of the rangers attend a course similar to the EMT intermediate class, they call it the Park Medic Course, it is taught once a year in Fresno, CA. Once they return to their home units, their local medical director can adjust their standing orders. If you are already a medic and looking for NPS work, keep your national registry up. My boss on YOSAR was a paramedic and kept his cert active and was frequently called on to utilize his skills. Plus it gave him a step up, cause their is usually a lack of Medical around.
kary