Stand on the South Rim and you're looking at close to two billion years of Earth's history, stacked in visible layers — almost half the age of the planet, sliced open and color-coded by era. This kicks off the Wildlands Grand Canyon trilogy, built the way the canyon was: rock first, then the people.

Host Shawn Spainhour, a former Army officer, traces the full arc. The geology: the 1.8-billion-year-old Vishnu Schist at the bottom, the Great Unconformity where a billion years of rock simply goes missing, the fossil reptile tracks in the Coconino Sandstone, and how the Colorado River cut straight down through all of it. The people: twelve thousand years of continuous human presence and the eleven tribes who hold living, legally recognized ties to this canyon today — including the Havasupai, and the recent renaming of Indian Garden back to Havasupai Gardens. Then the exploration and the fight: John Wesley Powell's one-armed, no-map 1869 boat expedition that lost three men, and the three-decade battle to protect the canyon — a president who called it un-improvable, a Park Service director, and a senator who ran a private tollbooth on the best trail and fought the Supreme Court to keep it.

This is Part 1 of the Wildlands Grand Canyon series. Part 2 covers the visit; Part 3 covers where to stay.

Wildlands — know the land before you reach it.