Recently, on a hike in the hills at the edge of Rapid City, my sister-in-law happened on a prairie rattlesnake sunning itself on a rock a few feet from the trail. She took stock of her surroundings, then gave the snake a wide berth and finished her hike, more aware of the landscape and without the accompaniment of her music play list. That story isn’t especially unusual or frightening, until it happens to you. Then it’s kind of a big deal. Your …