Yellowstone National Park imposed partial fire restrictions Friday.

Other restrictions go into effect in Grand Teton National Park and the Bridger-Teton National Forest on Sunday.

In Yellowstone, backcountry campfires have been banned, as has smoking in the backcountry. In Grand Teton and on the forest, the partial ban covers fires and barbecue grills except at established campgrounds and picnic areas.

In the forest, chain saws must have spark arresters, and the person using one must have a fire extinguisher handy. Portable stoves that run on gas, petroleum and pressurized fuel are not affected by the bans.

Fireworks are illegal in the national parks, the forest and on private, BLM and state lands in Teton County.

“The fact that we’re going into restrictions shows you how concerned we are,” Bridger-Teton fire specialist Andy Norman said.

The new restrictions coincide with continued steady growth of the Fontenelle Fire, the largest in the state, located 70 miles south of Jackson. Friday afternoon it covered approxmately 37,000 acres and was expected to be larger by the time an evening account had been made.

Fontenelle moved out of the heavy timber on the Bridger-Teton onto more manageable terrain owned by the Bureau of Land Management on Friday, officials said.

“It’s crossed the Middle Piney drainage and Fish Creek,” BLM public information officer Shelley Gregory said. “There’s a different fuel type on BLM land — more grass and sagebrush. That’ll allow us to confront the fire more directly.”

Area fire managers are contemplating increasing the fire danger rating.

“If it doesn’t rain, I’d expect we’ll go to very high within the next few days,” Norman said.