JACKSON (WNE) — Fire danger in Yellowstone National Park has risen to “very high” with stricter restrictions on campfires going into effect Saturday. The designation is exceeded only by an “extreme” fire danger rating.

Fireworks are not allowed in the park, and many waterways also have closed to fishing due to high water temperatures and historically low flows.

Wildfire activity is increasing, according to a Yellowstone news release, citing four lightning-caused fires that firefighters have responded to in the last week. Three of the four fires were 1/10th of an acre, while one grew to a half-acre. All are noted as “controlled,” on the park’s website. “Stage 1” fire restrictions which apply to campfires and smoking, will go into effect Saturday.

“Now is the time for visitors to be vigilant about fire safety,” Yellowstone warned in the Thursday update. “Negligently starting a wild land fire may result in fines and/or imprisonment.”

The fire restrictions include a prohibition on charcoal and all campfires in the backcountry, including those using established fire rings.

Smoking is allowed only in areas adjacent to the provided fire ring in designated campsites or within a 3-foot-diameter area barren of all flammable material. Smokers should ensure that all cigarette butts are extinguished properly.

Portable gas stoves and lanterns also are permitted in areas that are “barren or cleared of all overhead and surrounding flammable materials within 3 feet.”

Campfires are allowed at day-use picnic areas and developed campgrounds such as Madison, Mammoth, Slough Creek, Canyon, Indian Creek, Lewis Lake, Grant Village and Bridge Bay.

However, fires must be attended and cold to the touch before campers depart their campsites: Soak, stir, feel, repeat.