About The Author

Mark Seyler was a special agent with the ​Federal Bureau of Investigation for 26 ​years. During his career, he led high-​profile cases related to terrorism, ​corruption, organized crime, and fraud. ​Since retiring, he has used his ​experience to train law enforcement ​officers across the United States.


He is a sixth-generation Montanan who ​enjoys outdoor recreation under the Big ​Sky. This is his first book.


In 2021, the author received the FBI’s ​Medal of Excellence for his casework ​and the investigation described in Go ​Big or Go Home: Spies, Cops, and Oath ​Keepers Under the Big Sky

Buy and Read

Spies, Cops, and Oath Keepers Under the Big Sky

Click to buy Paperback, Hardcover or Kindle E-book

Drop shadow

Also available in Paperback

and Nook E-Book at

Barnes & Noble Online

Drop shadow

Return to

Main Page

Drop shadow