Yes actually there is an age limit for federal government employees - a convoluted age discrimination wrapped up in a bulky policy that has something to do with 30 years of service (or possibly 20 years for law enforcement) - you can' t join over the age of 38.  Check any National Park Service ranger job on usajobs.com (law enforcement or the other sub types of ranger that are not law enforcement).  I met up with a ranger in Mesa Verde National Park that was over 58, he explained that he hired on as a seasonal, non-law enforcement because that was the only thing he was legally permitted to sign up for per fed govt regulations.  No the states can' t discriminate in age but the federal government can...

If you keep clicking around and go deep enough into the ranger jobs on usajobs.com - you' ll see all sorts of lovely discrimination policies on having perfect eyesight, no weight issues, never been diagnosed with toe fungus....the list I found absolutely stunned me.  They wanted a test tube person created in a lab.  The reason I found all this is (in case you' ve read this far and are asking yourself) is because in a recent visit to Acadia National Park, I was floored to see a non-law enforcement NPS ranger who was likely 450 lbs, and unable to pick up a pen off the floor - made me wonder what the requirements were.  Between the 58 yr old ranger and the morbidly obese ranger - I had to find out.   The standards to get in are strict as heck; the standards to stay don' t exist.