The saguaro census, done every ten years, provides valuable long-term information on the state of the park's namesake plant.
NPS
Scientific research is key to protecting the natural and cultural wonders of our national parks. To make sound decisions, park managers need accurate information about the resources in their care. They also need to know how park ecosystems change over time, and what amount of change is normal.
Saguaro National Park is unique among national parks in that science was part of its original establishment proclamation. In 1928, University of Arizona president Homer L. Shantz, a plant scientist, looked at the desert east of Tucson and envisioned a vast outdoor laboratory, ranging from the cactus-studded desert to the pine-wreathed mountains, kept relatively free from human disturbance and studied by generations of student scientists. Buoyed by the support of local business boosters, Saguaro National Monument was created in 1933.
Today, science is an essential part of our mission and mandate. For more than 80 years, park scientists have collaborated with University of Arizona researchers to study saguaros, wildlife, and other Sonoran Desert resources. These studies have provided a wealth of knowledge that has helped guide conservation strategies to protect the park’s resources for future generations. NPS and university scientists continue to monitor saguaros on research plots that were established as early as 1941, in some of the longest-running monitoring programs in any national park.
Their work is supported by the Sonoran Desert Network, whose scientists collect long-term data on Saguaro National Park’s “vital signs.” Like a physician monitoring a patient's heartbeat and blood pressure, they monitor key resources, like climate, water, and vegetation. Then they analyze the results and report them to park managers. Knowing how key resources are changing can provide managers with early warning of potential problems. It can also help them to make better decisions and plan more effectively.
Research at Saguaro is also conducted by other state and federal scientists and independent researchers, and includes work on the park's rich history and cultural resources, as well. You can learn about recent research or generate a park species list below.
Locations:Acadia National Park, Allegheny Portage Railroad National Historic Site, Amistad National Recreation Area, Apostle Islands National Lakeshore, Appalachian National Scenic Trail, Appomattox Court House National Historical Park, Arches National Park, Assateague Island National Seashore, Big Bend National Park, Big Cypress National Preserve, Big Thicket National Preserve, Biscayne National Park, Boston Harbor Islands National Recreation Area, Buffalo National River, Cape Cod National Seashore, Capitol Reef National Park, Carl Sandburg Home National Historic Site, Carlsbad Caverns National Park, Channel Islands National Park, Chattahoochee River National Recreation Area, Chickasaw National Recreation Area, City Of Rocks National Reserve, Colorado National Monument, Congaree National Park, Crater Lake National Park, Craters Of The Moon National Monument & Preserve, Cumberland Island National Seashore, Cuyahoga Valley National Park, Delaware Water Gap National Recreation Area, Denali National Park & Preserve, Devils Tower National Monument, Dinosaur National Monument, Everglades National Park, Fort Larned National Historic Site, Gateway National Recreation Area, Glacier National Park, Glacier Bay National Park & Preserve, Glen Canyon National Recreation Area, Golden Gate National Recreation Area, Grand Canyon National Park, Grand Portage National Monument, Grand Teton National Park, Great Basin National Park, Great Sand Dunes National Park & Preserve, Great Smoky Mountains National Park, Gulf Islands National Seashore, Hawaiʻi Volcanoes National Park, Home Of Franklin D Roosevelt National Historic Site, Homestead National Historical Park, Horseshoe Bend National Military Park, Hot Springs National Park, Indiana Dunes National Park, Isle Royale National Park, Jean Lafitte National Historical Park and Preserve, John Day Fossil Beds National Monument, Joshua Tree National Park, Katahdin Woods and Waters National Monument, Katmai National Park & Preserve, Kenilworth Park & Aquatic Gardens, Klondike Gold Rush National Historical Park, Knife River Indian Villages National Historic Site, Lake Clark National Park & Preserve, Lake Roosevelt National Recreation Area, Lassen Volcanic National Park, Lewis and Clark National Historical Park, Lowell National Historical Park, Mammoth Cave National Park, Marsh - Billings - Rockefeller National Historical Park, Minute Man National Historical Park, Mississippi National River & Recreation Area, Monocacy National Battlefield, Montezuma Castle National Monument, Mount Rainier National Park, Natchez Trace Parkway, Natchez Trace National Scenic Trail, New River Gorge National Park & Preserve, Niobrara National Scenic River, North Cascades National Park, Ocmulgee Mounds National Historical Park, Olympic National Park, Oregon Caves National Monument & Preserve, Ozark National Scenic Riverways, Padre Island National Seashore, Petersburg National Battlefield, Pictured Rocks National Lakeshore, Pinnacles National Park, Pipestone National Monument, Prince William Forest Park, Redwood National and State Parks, Richmond National Battlefield Park, Rio Grande Wild & Scenic River, Rock Creek Park, Rocky Mountain National Park, Saguaro National Park, Saint Croix National Scenic Riverway, Saint-Gaudens National Historical Park, San Juan Island National Historical Park, Santa Monica Mountains National Recreation Area, Saugus Iron Works National Historic Site, Sequoia & Kings Canyon National Parks, Shenandoah National Park, Sleeping Bear Dunes National Lakeshore, Tallgrass Prairie National Preserve, Timucuan Ecological & Historic Preserve, Tumacácori National Historical Park, Tuzigoot National Monument, Upper Delaware Scenic & Recreational River, Valles Caldera National Preserve, Voyageurs National Park, Weir Farm National Historical Park, Wind Cave National Park, Women's Rights National Historical Park, Yellowstone National Park, Yosemite National Park, Yucca House National Monument, Zion National Parkmore »
Offices:Air Resources Division, National Natural Landmarks Program, Natural Resource Stewardship and Science Directorate
Read the abstract and get the link to a published paper on a model to predict mercury risk park waterbodies: Kotalik, C.J. et al. 2025. Ecosystem drivers of freshwater mercury bioaccumulation are context-dependent: insights from continental-scale modeling. Environmental Science & Technology. DOI: 10.1021/acs.est.4c07280
Locations:Carlsbad Caverns National Park, Chiricahua National Monument, Coronado National Memorial, Fort Bowie National Historic Site, Gila Cliff Dwellings National Monument, Montezuma Castle National Monument, Saguaro National Park, Tuzigoot National Monumentmore »
The National Park Service is implementing the restoration of native amphibians in over 20 sensitive wetlands across eight southwestern national parks. However, there's a particular threat (that croaks) that requires the NPS and partners to collaborate and innovate to find solutions.
The Sonoran Desert Network uses remote wildlife cameras to monitor mammals in the Tucson Mountain District of Saguaro National Park. In 2023, we deployed 59 wildlife cameras and collected 3,967 photos of mammals. We analyze the photos using single-season occupancy models to find out how mammals use the park and to understand the pressures that affect mammal distribution across the landscape.
Sidewinder snakes are small creatures that face big threats. They play a crucial role in the desert ecosystem of Saguaro National Park in Arizona. Scientists conducted a species inventory to find out how rare this species is in the park, and if actions are needed to protect it.
Locations:Acadia National Park, Agate Fossil Beds National Monument, Alibates Flint Quarries National Monument, Amistad National Recreation Area, Antietam National Battlefield, Apostle Islands National Lakeshore, Appalachian National Scenic Trail, Arches National Park, Assateague Island National Seashore, Aztec Ruins National Monument, Badlands National Park, Bandelier National Monument, Bent's Old Fort National Historic Site, Big Bend National Park, Big Cypress National Preserve, Big Hole National Battlefield, Big South Fork National River & Recreation Area, Big Thicket National Preserve, Bighorn Canyon National Recreation Area, Biscayne National Park, Black Canyon Of The Gunnison National Park, Blue Ridge Parkway, Bryce Canyon National Park, Buffalo National River, Cabrillo National Monument, Canyon de Chelly National Monument, Canyonlands National Park, Cape Cod National Seashore, Cape Hatteras National Seashore, Cape Lookout National Seashore, Capitol Reef National Park, Capulin Volcano National Monument, Carlsbad Caverns National Park, Casa Grande Ruins National Monument, Catoctin Mountain Park, Cedar Breaks National Monument, Chaco Culture National Historical Park, Chamizal National Memorial, Channel Islands National Park, Chattahoochee River National Recreation Area, Chesapeake & Ohio Canal National Historical Park, Chickasaw National Recreation Area, Chiricahua National Monument, Colorado National Monument, Congaree National Park, Coronado National Memorial, Cowpens National Battlefield, Crater Lake National Park, Craters Of The Moon National Monument & Preserve, Cumberland Island National Seashore, Curecanti National Recreation Area, Cuyahoga Valley National Park, Death Valley National Park, Delaware Water Gap National Recreation Area, Devils Postpile National Monument, Devils Tower National Monument, Dinosaur National Monument, Dry Tortugas National Park, Ebey's Landing National Historical Reserve, Effigy Mounds National Monument, El Malpais National Monument, El Morro National Monument, Everglades National Park, Fire Island National Seashore, Florissant Fossil Beds National Monument, Fort Bowie National Historic Site, Fort Larned National Historic Site, Fort Union National Monument, Fort Vancouver National Historic Site, Fossil Butte National Monument, Gettysburg National Military Park, Gila Cliff Dwellings National Monument, Glacier National Park, Glen Canyon National Recreation Area, Golden Gate National Recreation Area, Golden Spike National Historical Park, Grand Canyon National Park, Grand Canyon-Parashant National Monument, Grand Portage National Monument, Grand Teton National Park, Grant-Kohrs Ranch National Historic Site, Great Basin National Park, Great Sand Dunes National Park & Preserve, Great Smoky Mountains National Park, Guadalupe Mountains National Park, Gulf Islands National Seashore, Hagerman Fossil Beds National Monument, Hopewell Culture National Historical Park, Hovenweep National Monument, Indiana Dunes National Park, Isle Royale National Park, Jean Lafitte National Historical Park and Preserve, Jewel Cave National Monument, John Day Fossil Beds National Monument, John Muir National Historic Site, Joshua Tree National Park, Juan Bautista de Anza National Historic Trail, Katahdin Woods and Waters National Monument, Lake Mead National Recreation Area, Lake Meredith National Recreation Area, Lake Roosevelt National Recreation Area, Lassen Volcanic National Park, Lava Beds National Monument, Lewis & Clark National Historic Trail, Little Bighorn Battlefield National Monument, Lyndon B Johnson National Historical Park, Mammoth Cave National Park, Marsh - Billings - Rockefeller National Historical Park, Mesa Verde National Park, Mississippi National River & Recreation Area, Missouri National Recreational River, Mojave National Preserve, Montezuma Castle National Monument, Mount Rainier National Park, Mount Rushmore National Memorial, Muir Woods National Monument, Natchez Trace Parkway, National Capital Parks-East, Natural Bridges National Monument, Navajo National Monument, New River Gorge National Park & Preserve, Niobrara National Scenic River, Noatak National Preserve, Obed Wild & Scenic River, Olympic National Park, Oregon Caves National Monument & Preserve, Organ Pipe Cactus National Monument, Ozark National Scenic Riverways, Padre Island National Seashore, Pecos National Historical Park, Petrified Forest National Park, Petroglyph National Monument, Pictured Rocks National Lakeshore, Pipe Spring National Monument, Point Reyes National Seashore, Redwood National and State Parks, Rio Grande Wild & Scenic River, Rock Creek Park, Rocky Mountain National Park, Saguaro National Park, Saint Croix National Scenic Riverway, Salinas Pueblo Missions National Monument, Sand Creek Massacre National Historic Site, Santa Monica Mountains National Recreation Area, Scotts Bluff National Monument, Sequoia & Kings Canyon National Parks, Shenandoah National Park, Sleeping Bear Dunes National Lakeshore, Sunset Crater Volcano National Monument, Tallgrass Prairie National Preserve, Theodore Roosevelt National Park, Timpanogos Cave National Monument, Timucuan Ecological & Historic Preserve, Tonto National Monument, Tule Lake National Monument, Tule Springs Fossil Beds National Monument, Tumacácori National Historical Park, Tuzigoot National Monument, Upper Delaware Scenic & Recreational River, Valles Caldera National Preserve, Voyageurs National Park, Walnut Canyon National Monument, Washita Battlefield National Historic Site, Whiskeytown National Recreation Area, White Sands National Park, Wilson's Creek National Battlefield, Wind Cave National Park, Wupatki National Monument, Yellowstone National Park, Yosemite National Park, Yucca House National Monument, Zion National Parkmore »
Across the US, changes in water availability are altering which plants grow where. These changes are evident at a broad scale. But not all areas experience the same climate in the same way, even within the boundaries of a single national park. A new dataset gives park managers a valuable tool for understanding why vegetation has changed and how it might change in the future under different climate-change scenarios.
Each park-specific page in the NPS Geodiversity Atlas provides basic information on the significant geologic features and processes occurring in the park. Links to products from Baseline Geologic and Soil Resources Inventories provide access to maps and reports.
Climate and water shape ecosystems and the services they provide, particularly in arid places like the Sonoran Desert. We monitor climate, groundwater, and 16 springs at the park to help managers protect park resources. Understanding how climate and water may be changing over time can also help explain changes in plants and animals on the park.
Locations:Hopewell Culture National Historical Park, Hopewell Furnace National Historic Site, Horseshoe Bend National Military Park, Hot Springs National Park, Hovenweep National Monument, Hubbell Trading Post National Historic Site, Indiana Dunes National Park, Isle Royale National Park, Jean Lafitte National Historical Park and Preserve, Jewel Cave National Monument, John Day Fossil Beds National Monument, John Muir National Historic Site, Johnstown Flood National Memorial, Joshua Tree National Park, Kalaupapa National Historical Park, Kaloko-Honokōhau National Historical Park, Katmai National Park & Preserve, Kenai Fjords National Park, Kenilworth Park & Aquatic Gardens, Kennesaw Mountain National Battlefield Park, Kings Mountain National Military Park, Klondike Gold Rush National Historical Park, Knife River Indian Villages National Historic Site, Kobuk Valley National Park, Lake Clark National Park & Preserve, Lake Mead National Recreation Area, Lake Meredith National Recreation Area, Lake Roosevelt National Recreation Area, Lassen Volcanic National Park, Lava Beds National Monument, Lewis and Clark National Historical Park, Lincoln Boyhood National Memorial, Little Bighorn Battlefield National Monument, Little River Canyon National Preserve, Lyndon B Johnson National Historical Park, Mammoth Cave National Park, Manassas National Battlefield Park, Marsh - Billings - Rockefeller National Historical Park, Martin Van Buren National Historic Site, Mesa Verde National Park, Minute Man National Historical Park, Mississippi National River & Recreation Area, Missouri National Recreational River, Mojave National Preserve, Monocacy National Battlefield, Montezuma Castle National Monument, Moores Creek National Battlefield, Morristown National Historical Park, Mount Rainier National Park, Mount Rushmore National Memorial, Muir Woods National Monument, Natchez Trace Parkway, National Capital Parks-East, National Park of American Samoa, Natural Bridges National Monument, Navajo National Monument, New River Gorge National Park & Preserve, Nez Perce National Historical Park, Ninety Six National Historic Site, Niobrara National Scenic River, Noatak National Preserve, North Cascades National Park, Obed Wild & Scenic River, Ocmulgee Mounds National Historical Park, Olympic National Park, Oregon Caves National Monument & Preserve, Organ Pipe Cactus National Monument, Oxon Cove Park & Oxon Hill Farm, Ozark National Scenic Riverways, Padre Island National Seashore, Palo Alto Battlefield National Historical Park, Pea Ridge National Military Park, Pecos National Historical Park, Petersburg National Battlefield, Petrified Forest National Park, Petroglyph National Monument, Pictured Rocks National Lakeshore, Pinnacles National Park, Pipe Spring National Monument, Pipestone National Monument, Piscataway Park, Point Reyes National Seashore, Presidio of San Francisco, Prince William Forest Park, Puʻuhonua o Hōnaunau National Historical Park, Rainbow Bridge National Monument, Redwood National and State Parks, Richmond National Battlefield Park, Rock Creek Park, Rocky Mountain National Park, Russell Cave National Monument, Sagamore Hill National Historic Site, Saguaro National Park, Saint Croix National Scenic Riverway, Salinas Pueblo Missions National Monument, San Antonio Missions National Historical Park, San Juan Island National Historical Park, Sand Creek Massacre National Historic Site, Santa Monica Mountains National Recreation Area, Saratoga National Historical Park, Saugus Iron Works National Historic Site, Scotts Bluff National Monument, Sequoia & Kings Canyon National Parks, Shenandoah National Park, Shiloh National Military Park, Sitka National Historical Park, Sleeping Bear Dunes National Lakeshore, Stones River National Battlefield, Sunset Crater Volcano National Monument, Tallgrass Prairie National Preserve, Theodore Roosevelt National Park, Theodore Roosevelt Island, Thomas Stone National Historic Site, Timpanogos Cave National Monument, Timucuan Ecological & Historic Preserve, Tonto National Monument, Tumacácori National Historical Park, Tuzigoot National Monument, Upper Delaware Scenic & Recreational River, Valles Caldera National Preserve, Valley Forge National Historical Park, Vanderbilt Mansion National Historic Site, Vicksburg National Military Park, Virgin Islands National Park, Voyageurs National Park, Walnut Canyon National Monument, War In The Pacific National Historical Park, Washita Battlefield National Historic Site, Weir Farm National Historical Park, Whiskeytown National Recreation Area, White Sands National Park, Whitman Mission National Historic Site, Wilson's Creek National Battlefield, Wind Cave National Park, Wolf Trap National Park for the Performing Arts, Wrangell - St Elias National Park & Preserve, Wright Brothers National Memorial, Wupatki National Monument, Yellowstone National Park, Yosemite National Park, Yucca House National Monument, Yukon - Charley Rivers National Preserve, Zion National Parkmore »
To steward amphibians effectively, managers need basic information about which species live in parks. But species lists need constant maintenance to remain accurate. Due to recent efforts, the National Park Service now has an up-to-date amphibian species checklist for almost 300 parks. This information can serve as the basis for innumerable conservation efforts across the nation.
Locations:Carlsbad Caverns National Park, Chiricahua National Monument, Coronado National Memorial, Fort Bowie National Historic Site, Gila Cliff Dwellings National Monument, Montezuma Castle National Monument, Saguaro National Park, Tuzigoot National Monumentmore »
The American bullfrog is a great threat to aquatic ecosystems in the Southwest. They are voracious predators of aquatic animals and carry diseases that kill native species. We will implement three main actions in this project funded by the Inflation Reduction Act, Invasive Species Grant: bullfrog control, native species recovery and reintroduction, and development of early detection/rapid response protocols for bullfrogs.
Locations:Arches National Park, Canyon de Chelly National Monument, Canyonlands National Park, Capitol Reef National Park, Colorado National Monument, Death Valley National Park, Dinosaur National Monument, El Malpais National Monument, El Morro National Monument, Glen Canyon National Recreation Area, Hovenweep National Monument, Joshua Tree National Park, Mesa Verde National Park, Mojave National Preserve, Natural Bridges National Monument, Navajo National Monument, Petrified Forest National Park, Petroglyph National Monument, Rainbow Bridge National Monument, Saguaro National Park, Walnut Canyon National Monument, Yosemite National Park, Zion National Parkmore »
Offices:Geologic Resources Division
Ever wondered what those dark lines were on the rock walls of canyon country? These black, brown, and red streaks are called desert varnish.
Occurrence values are defined below. One or more Occurrence Tags may be associated with each Occurrence value.
Present: Species occurs in park; current, reliable evidence available.
Probably Present: High confidence species occurs in park but current, verified evidence needed.
Unconfirmed: Species is attributed to park but evidence is weak or absent.
Not In Park: Species is not known to occur in park.
Occurrence Tags
Adjacent: Species is known to occur in areas near to or contiguous with park boundaries.
False Report: Species was reported to occur within the park, but current evidence indicates the report was based on misidentification, a taxonomic concept no longer accepted, or other similar problem of error or interpretation.
Historical: Species' historical occurrence in park is documented. Assigned based on judgment as opposed to determination based on age of the most recent evidence.
Abundance
Abundant:
Animals: May be seen daily, in suitable habitat and season, and counted in relatively large numbers.
Plants: Large number of individuals; wide ecological amplitude or occurring in habitats covering a large portion of the park.
Common:
Animals: May be seen daily, in suitable habitat and season, but not in large numbers.
Plants: Large numbers of individuals predictably occurring in commonly encountered habitats but not those covering a large portion of the park.
Uncommon:
Animals: Likely to be seen monthly in appropriate habitat and season. May be locally common.
Plants: Few to moderate numbers of individuals; occurring either sporadically in commonly encountered habitats or in uncommon habitats.
Rare:
Animals: Present, but usually seen only a few times each year.
Plants: Few individuals, usually restricted to small areas of rare habitat.
Occasional:
Animals: Occurs in the park at least once every few years, varying in numbers, but not necessarily every year.
Plants: Abundance variable from year to year (e.g., desert plants).
Unknown: Abundance unknown
Nativeness
Native: Species naturally occurs in park or region.
Non-native: Species occurs on park lands as a result of deliberate or accidental human activities.
Unknown: Nativeness status is unknown or ambiguous.
List Differences
The Checklist contains only those species that are designated as "present" or "probably present" in the park.
The Full List includes all the checklist species in addition to species that are unconfirmed, historically detected, or incorrectly reported as being found in the park. The full list also contains species that are "in review" because their status in the park hasn't been fully determined. Additional details about the status of each species is included in the full list.
The checklist will almost always contain fewer species than the full list.
