Record dry heat and stiff winds helped two wildfires in northeast Jackson County each grow by more than 1,000 acres as flames jumped trails and fire lines, forcing firefighters to pull back from direct attacks.

The Blanket Creek fire in the Rogue River-Siskiyou National Forest nearly doubled in size from Wednesday and was listed Thursday morning at 2,432 acres and just 7 percent contained.

Nearby, the Spruce Lake fire in the northwest corner of Crater Lake National Park zoomed to 2,425 acres and growing, largely unchecked so far, to the east inside the park, with wind-whipped embers triggering spotfires as far as a mile away.

"There was not much that could be done on the east end of the fire," fire spokeswoman Koshare Eagle said. "It grew about 2½ miles to the east. All the growth has been to the east."

Crews who are part of the nearly 200 people assigned to the fire focused their efforts on fortifying the west side to flank it and keep it from moving in that direction should winds shift, Eagle said.

The fire also jumped the Pacific Crest Trail from west to east, proving that trail's Tuesday closure was prudent, Eagle said.

The Spruce Lake fire was listed this morning at 5 percent contained, with part of the Pacific Crest Trail as well as the Bald Crater Loop Trail and the Bert Creek Trail still closed to the public.

Meanwhile, Forest Service crews on the Blanket Creek fire near Red Blanket Mountain northeast of Prospect are dealing with similarly troublesome conditions, as that fire jumped containment lines built around Forest Service roads at the north and south ends of the fire, Eagle said.

Crews were forced to pull back there, with nature's only break coming in the fire's northeast area where flames have been slowed in huckleberry fields still moist from last winter's heavy snowpack, Eagle said.

Flames continue to push into steep terrain with heavy timber, according to the Forest Service.

Both fires were caused by lightning strikes last week, and firefighting resources continue to move in to fight the blazes, Eagle said.

The state Department of Environmental Quality Thursday issued bad-air warnings throughout Western Oregon, including Medford and Shady Cove.

Medford's air was listed as moderate for particulate matter associated with smoke, while Shady Cove's air was listed as unhealthy for sensitive groups such as younger and older residents, as well as those with respiratory problems, according to DEQ.

The air quality could be influenced from smoke coming from as far away as the 80,365-acre Modoc July Complex fire burning in Northern California east of Clear Lake in Modoc County.

Air conditions were listed Thursday as moderate for Grants Pass, Cave Junction and the Provolt area due to smoke from the 3,636-acre Chetco Bar fire burning deep within the Kalmiopsis Wilderness Area.

That fire remains listed as zero percent contained, according to the Forest Service. 

— Reach Mail Tribune reporter Mark Freeman at 541-776-4470 or mfreeman@mailtfribune.com. Follow him on Twitter at www.twitter.com/MTwriterFreeman.