A fire that raced through Bass River State Forest in New Jersey’s Pinelands region had burned 5,000 acres as of Thursday evening, making it the largest wildfire of the year so far.

The New Jersey Forest Fire Service said it is working to contain the fire burning in the area of Allen Road in Ocean County. As of 6 p.m. Thursday, firefighters had contained 50% of the blaze, which began Wednesday night.

Multiple roads are closed and the Timberline Campground has been evacuated. Local fire companies are also responding.

The Batona Trail, a 53-mile path through the pine barrens, is closed as it crosses through Bass River State Forest.

Although the risk of fire is listed as moderate Thursday, it is prime wildfire season and May was unusually dry. Officials said a backfiring operation, or a fire set intentionally along the fire line, helped in the containment.

It marks the second major wildfire this year.

In April, a wildfire tore through 3,859 acres in an area of heavily forested South Jersey that was rimmed by homes, businesses and military installations. It took days to contain and was dubbed “Jimmy’s Waterhole fire” by the state Forest Fire Service.

That blaze that began in Manchester Township, Ocean County, initially threatened scores of buildings before being brought under control. No one was injured.

The current fire has been dubbed the Allen Road Wildfire. It began as a small brush fire Wednesday evening, growing to hundreds of acres while continuing to grow overnight, reaching 2,000 acres by early Thursday morning, then swelling to its current size by late morning.

Bass River State Forest is New Jersey’s oldest state forest and opened in 1905. It contains the popular Lake Absegami Natural Area and is within the Pinelands National Reserve, a one million acre protected area. It marks the southern end of the 53-mile-long Batona Trail that snakes through Wharton and Brendan Byrne State Forests.