Yellowstone: What to Know Before You Go

Short answer: treat Yellowstone's 230-kilometre Figure-8 Grand Loop Road as two separate full-day loops (the Lower Loop for geysers and the Lake, the Upper Loop for the Canyon, Mammoth and Lamar Valley wildlife), never step a single foot off the wooden boardwalks in thermal basins, keep 100 yards (91m) from bears and wolves and 25 yards (23m) from bison, and download offline maps because 85% of the park has zero mobile service.

1. How Yellowstone's 'Figure-8' Grand Loop Road Works

Because Yellowstone covers nearly 9,000 square kilometres at an average elevation of 2,400 metres (8,000 feet), its paved roads form a giant 230-kilometre (142-mile) Figure-8 in the middle of the park, fed by five entrance spokes:

• The Lower Loop (154 km / 96 Miles, Geysers, Lake & Canyon): links Old Faithful, Grand Prismatic Spring, West Thumb & Yellowstone Lake, Hayden Valley and the Grand Canyon of the Yellowstone.
• The Upper Loop (112 km / 70 Miles, Terraces, Norris & Lamar Wildlife): links Norris Geyser Basin, Mammoth Hot Springs, Tower-Roosevelt, Mount Washburn and the northeast spur through Lamar Valley.

2. The 3 Life-Saving Safety Rules in Yellowstone

1. Never Step Off Thermal Boardwalks (Boiling Acid Water & Thin Crust): ground in geyser basins is a razor-thin mineral crust over 93°C (200°F) boiling water. Stay strictly on boardwalks, hold hats so they do not blow in, and keep pets out of thermal areas.
2. Bison Injure More Visitors Than Bears Every Year: a 900-kilogram bison can sprint at 55 km/h (35 mph, three times faster than you can run). Always stay at least 23 metres (25 yards, the length of two buses) from bison and elk, and 91 metres (100 yards) from bears and wolves.
3. Seasonal Road Dates: aside from the North-to-Northeast road (Gardiner → Mammoth → Lamar Valley), all park roads close to regular cars from November 1 until mid-April or May.