A selection of the images I’ve used for my book covers:
My Address is a River
Birds, Beetles, Bears and Beliefs
From Faith to Freethought
Highland Views
Beyond the Boundaries of Belief
Nature is Enough
A Freethinker’s Gospel
Was Jesus A Humanist?
Message on the Mountain
Friendly Freethinker
Simply Secular
The Affable Amiable Apostate
A Secular Gospel
Jesus and John Muir (novella)
One Nature Indivisible
Once Upon a Faith
Broken Bridges
Intersections
Eye to Eye
Edge of the Falls (poetry)
Friendly Freethinker 
Just a quick note to say you are one prolific dude. You write books in your sleep and I have been working on mine for 5 years and have yet to complete the final draft. You are inspiring Chris, but perhaps we have very different styles and habits. Undoubtedly. When I see your covers i want to go fishing or take a hike with you and chat.
A hike and chat would be wonderful, Marty, I’m sure. Guessing your book will be great, given the quality time, diligence and commitment to the value of humanist service. Cheers.
Thanks for the encouragement and prophetic analysis of my book before you have read it. Very gentlemanly of you. Do you ever get to Canada? I live in Vancouver and we have some of the greatest mountain hikes to found on our continent. Love to be your guide for a day. Do you fly fish?