New Mexico is growing.....just not he way you may be thinking. The Earth's crust in the state is stretching at a rate of an inch of east-west growth every 40 years, according to Scientists. Researchers had suspected this was happening because of the way the Rio Grande Rift splits the state down the middle. The rift, a tear in the Earth's crust, defines the state's central mountain chain and the valley the Rio Grande now follows.