A fairly easy hike to an interesting geological phenomena - the Tolsona Mud Volcanoes. Kids will love this one.

The mud "volcanoes" are created by methane gas, which comes from coal beds, bubbling up to the surface. On their journey upwards, the bubbles pass through fine silt, some of which is carried up with the bubble all the way to the surface. When the bubbles pop at the top, the tiny load of silt particles is deposited. The mud flats have been created by the deposition of specks of silt carried up by millions of bubbles over time - an oozing monument to the power of persistence.