Jump to ratings and reviews
Rate this book

Sam Rivers #3

Killing Monarchs

Rate this book
Two dead bodies and too many coincidences to ignore—in this outdoors mystery, special agent Sam Rivers must stop a murderous conspiracy. As a special agent for the US Fish & Wildlife Service, Sam Rivers has researched and studied a variety of animals. He’s visiting sixth graders at Hopkins Elementary to share photographs of the Monarch butterfly—and he’s brought along his drug-sniffing wolfdog, Gray, to give students a demonstration of his partner’s remarkable skills. Gray finds a sample drug packet, hidden by Sam, but that’s not all. The wolfdog keeps following his nose, leading Sam to a utility room where they discover the school’s janitor, dead. Local police write it off as a drug overdose, but Sam is no stranger to crime scenes. He suspects foul play. When Sam and Gray come upon a second victim, the coincidences are too great to ignore. Sam starts turning over rocks—and what slithers out is more insidious than anyone could have foretold. Sam’s instincts tell him there’ll be more deaths, but those instincts put him at odds with conventional law enforcement. Armed with his knowledge of the natural world and his wolfdog companion, Sam must uncover answers to questions that few others believe exist. The Denver Post calls Sam Rivers the “predator’s predator.” In Killing Monarchs , natural history writer Cary J. Griffith brings back Sam for his third mystery—a thrilling novel filled with action and suspense.

424 pages, Paperback

Published June 13, 2023

14 people are currently reading
2576 people want to read

About the author

Cary J. Griffith

11 books143 followers
Award-winning author Cary J. Griffith grew up among the woods, fields, and emerald waters of eastern Iowa. His childhood fostered a lifelong love of wild places.

He earned a B.A. in English from the University of Iowa and an M.A. in library science from the University of Minnesota.

Griffith’s books explore the natural world. In nonfiction, he covers the borderlands between civilization and wild places. In fiction, he focuses on the ways some people use flora and fauna to commit crimes, while others with more reverence and understanding of the natural world leverage their knowledge to bring criminals to justice.

He lives with his family in a suburb of Minnesota’s Twin Cities.

Ratings & Reviews

What do you think?
Rate this book

Friends & Following

Create a free account to discover what your friends think of this book!

Community Reviews

5 stars
47 (33%)
4 stars
66 (46%)
3 stars
26 (18%)
2 stars
2 (1%)
1 star
1 (<1%)
Displaying 1 - 19 of 19 reviews
Profile Image for Carla Black.
341 reviews84 followers
July 15, 2023
I won this book in a Goodreads Giveaway. I loved this book. Makes me want to read the rest of the series. This book definitely held my attention, didn't want to stop reading and couldn't wait until I had time to pick up again. Sam Rivers very intelligent officer. His drug sniffing wolfhound named Gray was thrilling to read about. I had a friend who had a wolfhound back in the 80's. They are beautiful creatures. Sam has a love interest also which it sounded like they fit perfectly for each other. This book contained really nasty characters from a nasty cartel. The way the cartel got info out of people was creepy but original. Along with the murder mystery, it also delved Into stories about conservation, flora and fauna, especially about Monarch butterflies. Which added to the story and did not take away from it. Better than I thought it was going to be from the description. The best mystery I have read in years. A+ to this book. You really need to read it.
Author 5 books
July 17, 2023
Killing Monarchs is not your ordinary detective novel. Griffith’s Sherlock is Sam Rivers, a US Fish and Wildlife agent; his Watson is Gray, a wolfdog (half arctic wolf, half malamute); and the criminals? Drug thugs, who call themselves Monarchs, migrate from Mexico to Minnesota, and kill with a scorpion sting. Rivers couldn’t detect the crimes committed by the Monarchs without Gray’s nose, and he couldn’t solve them without his knowledge and love of Nature. This novel is inspired and formed by Griffith’s love of flora and fauna. A great read!
191 reviews2 followers
July 23, 2023
Nice old fashion story. The good guys were the good guys and the bad guys were the bad guys. Interesting twist with the main characters being Sam Rivers of the US National Fish and Wildlife Service and his wolf hybrid dog. The description of the life cycle of the Monarch Butterfly added some color to the story. This is the third book about Sam Rivers written by the author. I am sure that most people would be interested in reading more adventures in the series.
233 reviews
August 6, 2023
Better than Cougar Claw, but the writing is still a bit clunky at points. I think the only reason I keep reading this series is because of the Minnesota setting and the fact that I know many of the locations where the action takes place. The whole monarch butterfly/heroin connection seems pretty implausible, but there is enough action and suspense to keep the plot moving if you don't stop to analyze what's happening.
Profile Image for Doug.
501 reviews4 followers
July 7, 2023
Griffith's Sam River mysteries just keep getting better. Killing Monarchs features truly nasty bad guys, a new love interest for Sam, and lots of action for Gray the wolfhound. Rivers is a character with whom it is easy to empathize. A bonus is the knowledge of wildlife and conservation brought into the story. Can't wait for the next one!
Profile Image for Jenny K.
31 reviews7 followers
August 18, 2023
I would like to Thank GoodReads as well as the author, Cary J. Griffith, for my free copy of “Killing Monarchs.”

I definitely recommend this book to anyone looking for an action packed… detail-oriented… page-turning… one-of-a-kind story written by a beyond talented author!

You won’t be disappointed… Promise!!
Profile Image for Sara P.
232 reviews
September 1, 2023
This book is book 3 of Sam river’s mysteries but can be read as a stand alone. I like how the book flowed, the characters were interesting, but I really kept thinking why is this USFW guy doing all this police work and why are the police letting him? Become a cop already or let them do it. But I would go back and read the other two books the author has written, so there’s that.
51 reviews1 follower
September 6, 2025
This Sam Rivers thriller brought back to Minnesota. He becomes involved with deaths that are tied to drug cartels and the vengence the 'bosses' wreak on others in and out of their organizations. It's hard to put down as a read and hard sometimes to continue reading; but every part of this book brings Sam and his life back into the world we live in. Exciting and hard to put down.
Profile Image for Annarella.
14.2k reviews165 followers
April 19, 2023
The first I read in this series and won't surely be the last as I appreciated the tightly knitted and fast paced plot and the great MC.
Highly recommended.
Many thanks to the publisher for this arc, all opinions are mine
Profile Image for Pam Sloss.
39 reviews1 follower
July 25, 2023
Cary J. Griffith has written a real attention-grabber! I had a hard time putting this book down. It's not your average detective story. Sam Rivers is a character you can feel like you know. Added value is the author's knowledge and vivid descriptors of nature and wildlife. Great read!
Profile Image for Darlene Christensen.
162 reviews1 follower
January 30, 2024
Sam Rivers, agent for USF&WE gets involved in a case of smuggling into central MInnesota. Murder of 2 young men who had served time in their teens were found with needles found in their arms. Sam and his dog Gray are on the case.
124 reviews10 followers
November 10, 2024
I struggled to get through the first 75 pages before deciding not to waste my time. Sorry isn't fluid, too much detail on unimportant things and not enough detail on the important things. Could have been good but wasn't.
Profile Image for Mary.
469 reviews2 followers
July 13, 2023
Gets better each book. A real surprise to me at the end of this book. And I learned things about Bark scorpions and Monarch butterflies.
Profile Image for Gloria.
1,656 reviews1 follower
September 15, 2023
Excellent police procedural. Lots of action, danger and good detective work. A little romance mixed in doesn't hurt.
162 reviews
September 30, 2025
It was ok and I sort of enjoyed it, but I don't think I'll be searching out more of the series.
256 reviews1 follower
Read
March 5, 2025
I got 50 or so pages into this and didn't like it so I gave up. The writing seemed flat, like reading a newspaper story about a crime.
Displaying 1 - 19 of 19 reviews

Can't find what you're looking for?

Get help and learn more about the design.