| Site Name | Description | Membership | |
|---|---|---|---|
| Adirondack Mountains | Adirondack Mountain granitic gneiss site, NY. Location in southwestern Adirondacks. | Request membership | |
| BigLink | Biosphere-Geosphere interactions: Linking climate change, weathering, soil formation and ecosystem evolution | Request membership | |
| Bonanza Creek LTER | Carbon in the Critical Zone: Biogeochemical Fluxes and Microbial Communities in a Moisture Gradient and Moisture Manipulation at Bonanza Creek LTER | Request membership | |
| Boulder Creek Critical Zone Observatory | Weathered profile development in the Rockies | Request membership | |
| Boulder Creek Watershed | Headwater catchments in Boudler Creek Watershed | Join | |
| Calhoun Soil-Ecosystem Research and Education Experiment | Long-term soil-ecosystem experiments (LTSEs) demonstrate how & why humanity is changing Earth's Critical Zone on decade's time scales. | Join | |
| Central Great Plains | Sites encompass a climatic gradient from eastern Colorado to eastern Kansas. | Join | |
| Christina River Basin CZO | An NSF supported CZO established to integrate 3 major processes governing the critical zone: the water cycle, the mineral cycle, and the carbon cycle. | Join | |
| Clear Creek Observatory | Clear Creek River Basin | Request membership | |
| Domain #1 - Northeast - Harvard Forest | Has developed integrated facilities for atmospheric, hydrological, ecological, geographical, and biodiversity studies. | Request membership | |
| Dryadbreen and Fardalen (Svalbard) | Two shale dominated catchments in the Arctic. | Join | |
| Georgia Coastal Ecosystems | Georgia Coastal Ecosystems LTER site encompassesing three adjacent sounds on the Georgia coast, including upland, intertidal and submerged habitats | Request membership | |
| Guadeloupe | Monitoring of soil solution, stream water chemistry and physical denudation | Request membership | |
| Hawaii | Linking Hydrology and Deep Weathering | Join | |
| Hubbard Brook Experimental Forest | The Hubbard Brook Experimental has a long history of hydrobiogeochemical research. Recently, new hydropedology studies have been established. | Request membership | |
| Illinois River Basin | Illinois River Basin | Request membership | |
| J. Phil Campbell Research and Education Center | Mission is to develop and transfer environmentally sustainable and profitable agricultural systems | Join | |
| Jemez River Basin and Santa Catalina Mountains CZO | A developing interdisciplinary observatory in the southwestern US | Request membership | |
| Kellogg Biological Station, Michigan | Kellogg Biological Station, Michigan | Request membership | |
| Koiliaris River Basin | Hydrologic and geochemical pathways in complex geomorphologic terrain. Soil degradation studies | Join | |
| Luquillo | The Luquillo Critical Zone Observatory (LCZO) will be located in Northeastern Puerto Rico in the USFS Luquillo Experimental Forest and at the USGS WEB | Request membership | |
| Lysina | Acid-sensitive catchment underlain by leucogranite, Czech Republic | Join | |
| Marcellus shale | Marcellus shale | Request membership | |
| Merced River Chronosequence | A Staircase Through Time and a Window into Human Disturbance of Biogeochemistry | Request membership | |
| Moorea Coral Reef LTER, French Polynesia | Moorea Coral Reef LTER, French Polynesia | Closed | |
| Muskingum Watershed | Muskingum Watershed | Request membership | |
| Nevada Climate-ecohydrological Assessment Network (NevCAN) Snake Range Transect | Valley-to-peak transect monitoring stations for the analysis of environmental responses to climate change in the Great Basin | Request membership | |
| North Ogilvie Mountains, Yukon Territory | Shale-derived soils in the unglaciated North Ogilvie Mts., Yukon Territory. | Request membership | |
| North Temperate Lakes LTER, Wisconsin | North Temperate Lakes LTER, Wisconsin | Request membership | |
| NorthEastern Soil Monitoring Cooperative | NorthEastern Soil Monitoring Cooperative | Request membership | |
| Panola Mountain | Panola Mountain | Request membership | |
| Pluhuv Bor | Serpentinite-dominated site in the Czech Republic. | Join | |
| Plum Island Ecosystems LTER, Massachusetts | PIE LTER studies the long-term response of coupled land-estuary-ocean ecosystems to changes in climate, sea level, and human activities. | Request membership | |
| Plynlimon | Paired catchment experiment on shale bedrock in the headwaters of the rivers Wye and Severn in mid-Wales, UK | Join | |
| Richardson Mountains, Yukon Territory | Shale-derived soils in the unglaciated western foothills of the Richardson Mts., Yukon Territory. | Request membership | |
| Roger's Glen, Chadwicks, NY | New York satellite site (associated with the Shale Hills CZO) located in Chadwicks, NY | Request membership | |
| SDEG - Sonoran Desert Environmental Gradient | Saguaro National Park | Request membership | |
| Southern Sierra Critical Zone Observatory | Kings River Experimental Watersheds - P300 series nested catchments | Request membership | |
| Strengbach catchment - OHGE | Granitic forested catchment in North East of France, monitored since 1986 | Request membership | |
| Susquehanna Shale Hills Critical Zone Observatory | Susquehanna Shale Hills | Request membership | |
| Susquehanna Shale Hills Transect | A transect of sites on Shale along the east coast of the US. | Request membership | |
| Trindle Road Appalachian Trail Diabase | Nested lysimeters installed in regolith developed on Triassic diabase | Join |
CZEN.org is funded by The National Science Foundation
