Not even a slew of ravaging hurricanes could knock out these national park treasures

They activated their emergency response plans, working hard to board up mainland structures and the park service's historic structures and treasures 7 nautical miles away on Cumberland Island.

But no human effort could block the power of Irma.

After the hurricane departed, residents saw boats stacked on top of each other or tossed onto the mainland, flooded streets and debris scattered everywhere.

The park service's mainland dock -- where up to 300 passengers daily could catch the ferry to Cumberland Island, the main attraction of Cumberland Island National Seashore -- had been almost destroyed.

While some tattered parts remained, the accessible dock was at the bottom of the St. Marys River.

A protected barrier island

Cumberland Island is one of Georgia's barrier islands, once home to plantation owners and the people they enslaved, later a playground for the Carnegies, and once famous for hosting the wedding of the late John F. Kennedy Jr. and Carolyn Bessette at the First African Baptist Church.

It's a key driver to the St. Marys economy, with campers and day trippers to the island also staying in town or nearby, strolling the riverside streets and eating in restaurants.

"The park service is an integral part of the vibrancy of our downtown. We value them and they value us," says St. Marys Mayor John Morrissey. "There's always a sense that we all care about our community."

Visits to the island "are a significant portion of our downtown economy, and it's very important that we work together," he says.

Luckily for St. Marys and the park service, the town's dock hadn't sustained much damage and could be modified to be used by the park's privately contracted ferry service.

Years of cooperation between the town and the park service meant that officials were able to negotiate an agreement for the park service to use the local dock within two months, even as the work to repair and adapt the dock was taking place.

Ferry service to the island was restored on November 12, two months after the hurricane hit the Georgia coast.

Cumberland was one of at least 16 National Park Service sites damaged by one of several hurricanes -- Harvey, Irma, Maria and Nate -- that pummeled the United States from mid-August through mid-October in 2017.

Hurricanes, fires and earthquakes

Responding to disasters is nothing new for the National Park Service, which has preassigned go teams ready to respond to emergencies at its 417 sites across the United States and its territories. (Of the 417 sites, just 59 are the so-called headliner National Parks.)

The Federal Emergency Management Agency has designated the NPS as lead agency for some types of emergency response, such as search and rescue, even for disasters in non-park areas.

"Every year, we have the threat of something happening," says Andrew Hower, the park service's deputy chief of emergency services. "The park superintendent and the park staff develop a plan based on whatever risks there are at a particular park."

For the National Park Service units in the Southeastern United States, it's mostly hurricanes -- and the associated tornadoes and flooding -- that are the major threat, he says. In other regions, it's earthquakes, landslides, severe winter storms, wildfires and associated flooding.

Once the safety of visitors and employees (whose homes may have been damaged or destroyed during the disaster) has been established, the park service moves to protect buildings and historic assets in immediate danger of being damaged or destroyed.

"We have some sensitive and priceless pieces of our national history, and wilderness laws and other rules that come into effect," says Hower. "We need to be able to preserve those (buildings and assets)."

Responding 'in real time'

Once the site has been stabilized, the park superintendent and incident responders assess what work needs to be done to reopen the park safely. That doesn't mean everything needs to be repaired, because repairs can take years.

And it's not just the park service that responds to the disaster. Often, the state emergency management agency and longtime park volunteers will respond and and help with cleanup. The nonprofit National Park Foundation started a disaster relief fund a couple of years ago to support emergency and repair efforts at the parks, especially those without local nonprofits to support them.

"We respond in real time," buying iPads with mobile apps for emergency operations or other needs, says Will Shafroth, the foundation's president. "Part of this effort is to try to minimize the bureaucracy."

The park service has already begun preparing for the 2018 hurricane season, which traditionally starts June 1 and runs through November 30.

"We are anticipating another strong hurricane season this year," says the park service's Hower.

While damage is still evident at the 16 National Park Service sites and their surrounding communities hit by hurricanes Harvey, Irma, Maria and Nate, they are mostly open for visitors -- albeit with some limitations.

Here's how those sites are doing.

Big Cypress National Preserve, Florida

Big Cypress National Preserve in southern Florida experienced massive flooding, power outages and severe mold problems in park facilities due to Irma. Fallen trees blocked backcountry areas and trails across the park, causing the nation's first national preserve to be closed to visitors for about a month.

All the affected facilities have reopened, and backcountry trails are now open, but the park is still clearing hazardous trees and debris to improve access.

Biscayne National Park, Florida

One of the top scuba spots in the United States, Biscayne National Park is nearly all water-based. That's why much of the damage assessments were made by a dive team, checking to see the impact of Irma on the underwater landscape and historic shipwrecks. While a few Stiltsville structures sustained minor damage, as did the lighthouse on Boca Chita Key, the boat docks were more severely damaged.

While both Boca Chita Key and Adams Key reopened within weeks of being hit, the entire park reopened on October 4 and the jetty walk and trail at the Dante Fascell Visitor Center reopened in March. Other repairs continue.

Canaveral National Seashore, Florida

Canaveral National Seashore staff found five boats lifted onto park lands after Irma, and a boathouse, boardwalk, boat ramp and dock had some damage. The barrier island's shoreline also experienced major erosion.

While much of the minor damage has been repaired, boardwalk repairs and an assessment of shoreline and erosion damage throughout the park are ongoing. The park is waiting on permit approval to repair the docks.

De Soto National Memorial, Florida

Although De Soto National Memorial was hit by two storms -- Tropical Storm Emily (a spin-off of Harvey) and Hurricane Irma -- the worst impact at the Tampa Bay site where conquistador Hernando de Soto landed in 1539 was downed trees and tree limbs.

Everglades National Park, Florida

Everglades National Park dominates southern Florida with its 1.5 million acres of mangroves, sawgrass marshes and upland forest. Irma destroyed one visitor center and heavily damaged park offices and another visitor center. Entire roads and campgrounds were submerged.

All areas of the park have reopened, and regular programs have resumed. A trailer where the former Gulf Coast Visitor Center stood serves as a temporary visitor contact station until a new one can be built. Missing channel markers and submerged debris still render navigation of park waters potentially hazardous and a mariners advisory remains in place.

Fort Matanzas National Monument, Florida

Central to the European nations fight for control in the New World, Fort Matanzas is still not providing ferry service to the historic fort on Rattlesnake Island because of Hurricane Irma damage to the dock and ferry boats. The visitor center, nature trail and park beaches -- all on the larger Anastasia Island -- are still open to the public.

Gulf Islands National Seashore, Florida and Mississippi

On the Florida side of the seashore, Hurricane Nate's October landfall severely damaged two of the park's main roads. It took nearly two months for repairs to be completed and for the roads to reopen.

On the Mississippi side of the park, the government boat dock and public fishing pier in the Davis Bayou Area were heavily damaged and remain out of service, and the park service is trailering and launching its boats. All other hurricane damage on the mainland has been repaired.

On West Ship Island, the severely damaged ferry pier, cross-island boardwalk and concession buildings have been repaired, while repairs continue on the island's park housing.

Fort Frederica National Monument, Georgia

Named for Frederick Louis, the Prince of Wales during the first half of the18th century, Fort Frederica was established by the British on St. Simons Island in 1736 by James Oglethorpe to protect the British outpost from the nearby Spanish. The British defeated the Spanish here in 1742 and Georgia remained a British colony until the American Revolution.

The visitor center and historic area is open to the public, but the nature trail is closed due to tree damage caused by Hurricane Irma. It is scheduled to reopen by September.

Ocmulgee National Monument, Georgia

Many different nations lived on this land, a prehistoric Native American site that is now Ocmulgee National Monument, for thousands of years. When the Mississippian Period began around 900 A.D., the people living here constructed mounds for their elite, which can be seen today.

After being hit by Irma, the park -- which is about 200 miles northwest of the Georgia coast -- lost power to the maintenance building for four days. The site lost some 150 trees but reopened a few days after the storm passed. It only needed a few weeks to remove trees blocking trails and roadways.

Cumberland Island National Seashore, Georgia

Irma destroyed Cumberland Island National Seashore's mainland ferry dock, closing the park for nine weeks through mid-November. The city, state and federal officials worked together to clean up the St. Marys mainland waterfront.

The ferry from the mainland still docks at Sea Camp Dock on the island but it still can't dock at the island's Dungeness Dock, which was damaged by the storm and is out of commission for the foreseeable future.

Public boaters can dock at Sea Camp Dock or at Plum Orchard Dock, which was not damaged by the storms.

San Juan National Historic Site, Puerto Rico

One of the largest fortifications built by Spain in the Caribbean, the foundation of the six-level Castillo San Felipe del Morro at this historic site was laid in 1539 but wasn't completed until 1787.

It repelled the British several times but these fortifications could not stop Hurricane Maria, which devastated the island of Puerto Rico. It destroyed homes and businesses and cut off power for much of the island's residents for months.

The historic site, which reopened key portions in late November, had to repair plaster and masonry walls, roofs, light fixtures and poles and replace missing windows and doors. There was mold that had to be remediated, in addition to the standard debris removal.

While the park is up and running, park officials do deal with weekly power outages, which doesn't affect the forts but shuts down the visitor center.

Big Thicket National Preserve, Texas

Hit by Hurricane Harvey last August, Big Thicket National Preserve in southeast Texas was closed for more than a week but didn't sustain any damage to its park buildings. However, the homes two employees were flooded by the storm.

Record flooding damaged some of the 30 miles of trails throughout the preserve -- which is home to nine ecosystems -- undermining the structural integrity of two large pedestrian bridges and destroying several trail boardwalks. An assessment team has surveyed the damage, and a formal project request has been filed. (The park is awaiting the funds to make the repairs.)

Padre Island National Seashore, Texas

Luckily for Padre Island, Hurricane Harvey moved slightly north before making landfall, which meant the seashore received mostly bayside damage caused by winds and rain as they headed back to sea. A secondary campground, Bid Island Basin, was damaged by wave action, but all the campsites there are now open.

Virgin Islands National Park, US Virgin Islands

Hurricanes Irma and Maria devastated the island of St. John.

The storms destroyed six houses and significantly damaged 13 more, which displaced a dozen staff members back to the mainland. They also flooded the park's reverse osmosis plant that generates potable water for Trunk Bay, which is often ranked as one of the top 10 beaches in the world.

Other impacts include the destruction of the Danish Quarters, which was the oldest building on the island, built in the 1600s; significant damage to the Annaberg Sugar Plantation built in the late 1700s; the sinking or washing ashore of 90 vessels within the park; damaged coral reefs; eroding of much of the shoreline; and the storm covered the main North Shore Road, parking areas and trails with debris.

The park reopened to visitors in December, and park staff and volunteers have made incredible progress since the storms hit.

All the beaches are open, and Trunk Bay has running potable water again, with showers and flushing toilets. All the trails are open except the Francis Bay boardwalk, which is still under repair.

The storm altered but did not destroy Trunk Bay's renowned 225-yard-long underwater snorkeling trail. Return visitors may notice the markers have moved slightly, but they can still follow the route and spot beautiful fish and coral.

Christiansted National Historic Site, US Virgin Islands

A 7-acre park centered on the Christiansted waterfront/wharf area, this historic site documents Denmark's efforts to colonize part of the Caribbean and enter the sugar trade, relying on enslaved people for labor there. More than 100,000 Africans would come through this wharf as part of the slave trade.

Hurricane Irma caused minimal damage at this historic site, but it didn't reopen until early December because of island-wide power outages. NPS recovery missions on St. Croix focused on safe public and employee access, cosmetic repairs and regaining power at the historic sites.

Salt River Bay National Historical Park and Ecological Preserve, St. Croix, US Virgin Islands

Salt River Bay is rich in human history and natural beauty. It is home to some of the Virgin Islands' largest remaining mangrove forests -- as well as coral reefs and a submarine canyon. It's also home to archaeological sites dating back to before and after the 1493 landing by Christopher Columbus, including prehistoric and colonial-era archaeological sites and ruins.

Hurricane Maria caused significant damage to Salt River Bay's Visitor Center, which remains closed. Visitors can go to the visitor center at Christiansted National Historic Site, 5 miles away, for more information on visiting Salt River Bay.