They are quite abundant within Grand Staircase - Escalante National Monument .
Thousands of these concretions weather out of outcrops of the Navajo Sandstone within south - central and southeastern Utah within an area extending from Zion National Park eastward to Arches and Canyonland national parks .
Thousands are quite abundant within Grand Staircase - Escalante National Monument .
Thousands of these concretions weather out of outcrops of the Navajo Sandstone within south - central and southeastern Utah within an area extending from Zion National Park eastward to Arches and Canyonland national parks .