Cole Maddox is a former Delta Force operative.
He is not considered a spy, per se, by anyone, including himself, but he is pretty darn close to the definition in that he has gone into dangerous situations in disguise or at least out of recognizable uniform in order to obtain vital intelligence or to remove from existence people who pose an imminent threat to his country.
When we first meet him he is still an active member of that elite U.S. military organization, a man who has spent a good number of the adult portion of his 35 years in highly dangerous, often undercover work in the black ops realm, dealing with intel and orders coming from intelligence agencies such as the CIA and NSA. On that initial meet he is acting as a waiter in the festive party to get access to a man who is planning a cyberattack on the US power grid. Maddox's purpose is not to be friendly. Catching up with him a bit afterwards, he is a civilian again due to events 'at work' that prompted his leaving, described later in that first adventure.
Maddox is a well-honed 35 year old man with "well-defined facial features, dirty-blond hair, and fit body, six foot two, about two hundred pounds". He is white but was raised by his Native American adopted father who, when we meet that man, has recently retired from the family's construction company in Montana. Maddox, we are told, had eschewed heading to college after high school choosing instead to travel "the US for a year working odd jobs before enlisting in the military. Once he was recruited into black ops, he needed a cover story, so told people back in Timber Ridge he was a safety inspector on an oil rig." It is to that community that Maddox has returned to live and work when the troubles we will follow him handle begin.