Skip to main content

Madison Limestone Aquifer

4 states · 270,000 sq km · confined
Stable

About the Madison Limestone Aquifer

The Madison Limestone Aquifer is a deep, extensive carbonate aquifer underlying much of the northern Rocky Mountain region. It produces thermal water in many areas and supports several major springs.

Area
270,000 km²
Depth Range
500–15,000 ft
States
4
Rock Type
Limestone

Key Facts

  • Extends from the Rocky Mountains to the western Dakotas
  • Can be over 15,000 feet deep in some basins
  • Produces geothermal water in Montana and Wyoming
  • Very slow recharge — water may be thousands of years old
  • Supplies rural communities and agricultural irrigation

States Overlying the Madison Limestone Aquifer

Explore Water Assets Over the Madison Limestone Aquifer

See every tracked spring, well, and water right that draws from this aquifer on our interactive map.

Open Map Explorer

Other Major Aquifers