Smoke from a wildfire in Big Cypress National Preserve has prompted closure of a major interstate highway connecting the east and west coasts of Florida. The shutdown of Interstate 75, also known as Alligator Alley, is into its fourth day, and may continue through the weekend.

The blaze, dubbed the Deep Fire, was sparked by a lightning strike on Wednesday, April 22. As of Friday evening it had burned between 9,500 and 10,000 acres, with the earliest containment predicted for Monday, April 27. The fire is burning on both the north and south sides of I-75, which runs through the northern portion of the park.

Poor visibility from smoke prompted the closure of 78 miles of I-75, the main highway connecting the Miami and Fort Lauderdale metro areas on Florida's east coast with the western side of the state. The closure is from Mile Marker 101 in Collier County to State Road 27 in Broward County. Traffic is being detoured onto U.S. Highway 41. State Road 29 from U.S. 41 north to Oil Well Road is also closed.

According to local news reports, this is longest shutdown of I-75 in recent memory, but officials are well-advised to be cautious. Even without poor visibility from smoke, Alligator Alley is considered by some to be one of the most dangerous highways in Florida, and officials are especially cautious about problems due to poor visibility.

In January 2002, fog was blamed for a chain reaction wreck on the road that resulted in three deaths and 13 injuries. On January 9, 2008, a mixture of fog and smoke from a brush fire caused a similar accident on I-4 in central Florida. Fifty vehicles, including about 20 tractor-trailers and tankers, were involved in that incident, which killed four people.

Due to the fire, the Bear Island Unit of Big Cypress National Preserve is closed for all recreational access until further notice. According to a park spokesman, no homes, backcountry camps or other structures are at risk due to the fire.

NPS and cooperators are using aircraft, ground crews, and engines to conduct burnout operations to suppress the fire along I-75. Away from the highways, existing control lines will provide opportunities to contain the fire at approximately 15,000 acres.

UPDATE: I-75 was still closed in both directions between mile markers 23 and 101 as of 8:15 p.m. (EDT) on Sunday, April 26.

If you have travel plans in the area, you can get updated status reports on the highway closure on the Florida Highway Patrol website.