Shark Valley is one of the most beloved and busiest destinations in all of sprawling Everglades National Park — a winding 15-mile asphalt loop where bikers, hikers and tram riders travel through glistening marsh often adorned with alligators, herons and other wildlife.

But Shark Valley has a rising problem: the surrounding waters of the River of Grass.

Flooding along a trail first created more than six decades ago has always been an issue, one long driven by the seasonal wet and dry cycles of the Everglades. But it’s becoming more common – the result of super soggy hurricanes, climate change and even efforts to raise water levels and restore the natural flow of a system long bottled up by roads and flood-control levees.

Alissa Jean Schafer, an outdoor enthusiast and the climate director at Private Equity Stakeholder Project, is a regular biker at Shark Valley and tries to visit the park around twice a month. One morning in early September, Schafer found herself biking through two miles of flooding on the east side of the trail. It was deep enough that she saw fish swim across the path.

“It was much more dramatically flooded than I was expecting, and it was way more flooded than the previous time that I had gone a few weeks prior,” said Schafer. “I didn’t know how long the flood would last. I was like ‘Maybe it’ll dry up around this bend. Nope. It’s still flooded.’ That continued for about two miles.”

Over the last few years, park managers have been drawing up ways to make the parts of Shark Valley that people use higher and dryer. They are hoping to secure money for the proposed plans, which would include elevation of the entrance and the trail used by tourist trams and bikers, the addition of shade structures for bikers and hikers and more parking spaces. The parking lot at the Shark Valley, on the south side of Tamiami Trail about 21 miles west of Krome Avenue, fills up early on most weekends — mostly with cars and SUVs holding bike racks.

“There is a whole project for Shark Valley to expand the parking area and to raise the road and fix some of our administrative buildings,” said Allyson Gantt, chief of communications and public affairs for Everglades National Park. “Now we are seeking funding.” In 2023, the National Park Service released a statement where they found there to be no significant environmental impact for the Shark Valley site plan, but according to Gantt the project remains several years off.

A history of high water

Flooding was an issue almost from the start in Shark Valley.

The trail was built in 1946 when Humble Oil company, now known as Exxon, decided to drill oil in that section of the Everglades. When Humble Oil decided the oil wells were not economically viable, the trail was added into the National Park system. The signature observation tower at the trail’s midway point was built in 1965 as part of mission 66, which was a construction program that added development to Everglades National Park for the National Park’s Service’s 50th anniversary. The park opened the Shark Valley trail to visitors the following year in 1966.

But just two years later, flood gates along Tamiami Trail were opened and the entirety of Shark Valley was inundated. This caused devastation to not only the trail, but wildlife as well. After two and a half years, the trail debris was removed and the trail repaired.

South Florida’s dry season is the best time to visit, roughly from November to April, when temperatures tend to be cooler and water levels lower in the surrounding marsh. The summer months can be up and down, depending on rainfall and hurricanes. But Everglades hydrologists say peak flooding occurs in October and November as the entire wet season’s outfall collects in the marsh and slowly flows south toward Florida Bay. So complaining that Shark Valley is too flooded during the wet season is a bit like saying hiking Mount Rainier in Washington state is too cold during winter.

Ricky Ramsingh, a tram tour guide at Shark Valley, said that since 2017, Shark Valley has only closed three to four times. Although flooding is common, the trail is still passable most of the time and the park closes entirely only in severe cases.

Tropical storms and hurricanes are the wild card for Shark Valley conditions. In 2017, the park was closed for three months after Hurricane Irma dumped a deluge on South Florida.

In January 2021, Shark Valley reopened after two months of closure from record-high flooding caused by Hurricane Eta that submerged the trail and parking lot. Michelle Collier, a hydrologist who had worked in the Everglades, wrote in an article published by National Park Service in 2020 after the hurricane where she mentioned that water levels had been the highest on record after rainfall and water management restoration.

In May 2023, the park also closed for 17 days for the repaving of the entirety of the tram trail, parking lot and entrance road to Shark Valley to preserve the quality of the road.

Besides the main loop trail at Shark Valley, there are also three walking trails: The Bobcat Boardwalk near the visitors center, the Otter Cave Hammock trail half a mile from the visitors center and the Borrow Pit trail next to the observation tower. Most of the year, the Otter Cave Hammock trail and the Borrow Pit trail are flooded. During the dry season the Borrow Pit trail was completely submerged. Walkable … but also a potential gator pool party.

Coming impact of climate change

Long-term, climate change in the form of sea-rise may be the biggest issue for traversing Shark Valley. Even bigger than the gators that sometimes flop themselves in the middle of the trail.

Randall Parkinson, a research associate professor at the Institute of Environment at Florida International University, believes it will require “crazy construction” to keep Shark Valley open by 2050.

As surrounding seas rise, the pressure will also raise groundwater under the Everglades and the rest of South Florida and the natural gravity-driven flow of drainage to the coasts will slow.

“As sea level has risen, it has reduced the slope of the groundwater table. When the slope is decreased, it flows more slowly, and in some locations it essentially backs up to cause localized flooding,” said Parkinson. “You can imagine there’s a lot of low-lying places that will flood in the Everglades with fresh water as sea level continues to rise.”

Of course, sea level rise will have more immediate effect on the coastal wetlands of the Everglades such as Flamingo and the Ten Thousand Islands, but the ripple effects will be felt across the inland marshes as well. Down the road, freshwater marshes will turn salty and the entire ecosystem of the Everglades will undergo radical changes.

The proof of sea rise can be seen in tidal gauges, like one in Key West. Its record, he said, shows the average sea level rise was 2.6 millimeters per year from the year 1913 until 2022. “Between 1993 and 2022 it has risen at five and a half millimeters per year.”

“If you look at the rate of sea level rise from 2003 to 2022 in Key West, it’s almost eight and a half millimeters,” said Parkinson. “This is a phenomenal acceleration in sea level rise that is caused by climate change and unlikely to stop in our lifetime.”

Shark Valley patrons have learned to adjust to flooding. Last October, Aitor Echeverria, a frequent Shark Valley visitor, took his bike out to the park.

After reaching the observation tower and returning down the winding path on the east side, Echeverria said he encountered water up to his ankles and had to walk his bike five miles. All in all, though, it was still a great experience in the wilds of the Glades.

“I felt adventurous,” said Echeverria. “It was refreshing. It’s a hot day and then you have water to wade through.”

If you go

With the wet season ending in the next couple of months, park spokesperson Gantt said activities will begin to ramp up, with more details coming in October.

“Starting in January, we’ll have more night programs, slough slogs, which are the wet hikes, where you walk off trail, bike tours and they are also planning a new behind the scenes van tour that’ll be about Everglades restoration along Tamiami Trail,” she said.

Here are some tips for visiting Shark Valley:

Arrive early: During the dry winter, the parking lot can fill quickly, meaning long waits at the entrance or parking along Tamiami Trail, which can result in tickets. Arriving at or before 9 a.m. when the park opens is the safest bet to secure a spot or getting through gate at all — particularly on weekends.

Prep for sun, bugs: There is little shade on the trial and, depending on the season, a lot of insects. Dress for the conditions and pack repellent and sun screen.

Hydrate: You’re surrounded by watery marsh along the 15-mile trial but there are no water fountains along the route. There is one at the observation tower, but it has long been out of service. The National Park Service suggests one gallon of water per person on this trail.

Check for flooding: The visitor center is open 9 a.m. to 5 p.m. daily. To find out how flooded the trail is and for more information on their current activities, the visitor center can be reached at: (305) 221-8776. The park address is 36000 SW 8th St, Miami, FL 33194.