Here's a short and to the point review of the Soma Cazadero tires out of Cyclo-cross Magazine.
Click on the image to read the whole thing. Glad to hear it is one of their "all time favorites for gravel and adventure" even though we are aware gravel is still in its infancy. We hope the Cazes live up to that statement over the years.
Cazaderos come in both blackwall and skinwall, 700c or 650b. 42mm width only (1.65").
Have you tried them yet?