As smoke calms in Fairbanks, fires are heating up elsewhere in the Interior.

Fires burning in the Chalkyitsik Complex, northeast of Fairbanks, have now reached record levels in the Build-up Index, which monitors fire season severity and flammability. The complex includes the Tractor Trail 2, Frozen Calf, Bearnose Hill and Tettjajik Creek Fires. All of the fires are lightning-caused.

Combined, the fires are burning across more than 311,000 acres.

The Upper Yukon Zone, the area in which the Chalkyitsik Complex fires are burning, was the hottest, driest area in the state on Wednesday, despite rainfall in other parts of Interior Alaska. With thunderstorms rolling through the region, over 7,000 lightning strikes were reported, with several occurring in the Upper Yukon.

Fire crews in the area are working to build dozer lines and are working with a natural barrier, as well as preparing to conduct a firing operation, according to the Alaska Interagency Coordination Center situation report.

In Fairbanks, smoke has gradually been clearing from the air over the last week. The respite room at Fairbanks Memorial Hospital closed at 5 p.m. Thursday, a result of the improving conditions.

Meanwhile, the Shovel Creek Fire, which was burning at Murphy Dome, is now 45 percent contained. Successful firing operations earlier this month have allowed crews to begin mop up on a good portion of the fire.

The flames showed moderate activity Thursday, and Northern Rockies Team 6 hosted a meeting at Ken Kunkel Community Center at 6 p.m. The team took command of the fire earlier in the week.

In the Chena River State Recreation Area, the Nugget Creek Fire is still burning. Recent mapping estimates the fire at roughly 19,000 acres.

The lightning-caused fire caused the closure of the Nugget Creek Cabin as well as Mastodon and Granite Tors trails. The cabin and the trails all remain closed, although river access has been reopened at mile 39.

Northwest of Delta Junction, crews are working in two divisions to prevent the Rainbow 2 Fire from reaching recreational cabins on Clear Creek, according to the interagency akfireinfo.com website. The fire is estimated to be about 12,000 acres.

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