Mary V was thinking of something else.
They reached the top without having seen a single snake.

Tango seemed somewhat surprised at this, but Mary V was not.

Mary V thought it was too hot even for rattlesnakes, and as for the dearth of lizards--well she supposed the snakes had eaten them all.

She had let Tango stop often to breathe, and whenever he did so she had looked south, scanning as much of the lower level as she could see, which was not the proper way to go about hunting snake dens, I assure you.

But at the top she permitted Tango to walk into the shade of a boulder that radiated heat like a stove but was still preferable to the blistering sunlight, and there she left him while she walked a little nearer the edge of the rimrock that topped the ridge on its southern side.
Once more she scanned the sweltering expanse of sagebrush, scant grass, many rock patches and much sand.