A major wildfire burning in Wharton State Forest in New Jersey has grown to 4,200 acres and is 40% contained, growing close to 1,000 acres overnight but also signaling progress in containing the blaze.

The blaze, dubbed the Mines Spung Wildfire, had burned through 4,200 acres at Wharton State Forest and was 40% contained as of 8:30 a.m. Saturday, the New Jersey Forest Fire Service said in an update.