#20. Wyoming

Scraping leftovers into a compost pile might not sound like a vacation activity, but on Natural Habitat Adventures’ new seven-day Yellowstone safari, composting is as essential to the experience as camping or hiking. While expert naturalists guide you in search of bison and wolf pups, you’ll also be on an industry-first zero-waste expedition. You’ll drink from reusable water bottles and dine on locally sourced food sans single-use plastics like straws, plates, and cups. Everything that can’t be composted or recycled locally is hauled back to the company’s headquarters in Boulder, Colorado, to be recycled, upcycled, or handed off to TerraCycle, an innovative company that specializes in the reuse of otherwise unprocessable waste. The hope is that the trip will inspire you with the landscape and wildlife while fostering habits you can take home. From $5,695 —S.P.