Four wildfires are burning large swaths of Colorado as high temperatures and low humidity contribute to prime burning conditions across the state. The effects from the smoke can be felt all the way to the Front Range, as state public health officials issued air quality alerts for older adults, children and those with sensitive conditions.

After days of uncontrolled growth, the Pine Gulch Fire remained relatively stable overnight and now sits at 74,807 acres and 7 percent containment as of Saturday morning.

Fire officials have focused all week on protecting Garfield 204, along which are residences and oil and gas operations.

The wildfire, burning 18 miles north of Grand Junction since July 31, remains the fourth-largest in Colorado’s recorded history.

Meanwhile, the Grizzly Creek Fire Glenwood Canyon grew 5,000 acres overnight and is now burning nearly 20,000 acres.

Winds were favorable Friday, and fire lines held in the No Name drainage as the fire stayed low in the canyon without spreading across the drainage, Grizzly Creek Fire officials said Saturday morning on the incident webpage.

Bureau of Land Management recreation sites and boat ramps have been closed on the southern part of Colorado River Road near Dotsero, including Cottonwood Landing boat ramp, Lyons campground and boat ramp, and Dotsero boat ramp.

Saturday’s weather will remain hot and dry with moderate winds, officials said. Crews will focus on protecting structures in the areas of Spring Valley, High Aspen and Lookout Mountain, as well as No Name, Shoshone Power Station, Bair Ranch and Dotsero.

Officials warned residents near the fire to remain ready for evacuation or pre-evacuation notices as the wildfire continues to move. That information can be found on the Garfield County and Eagle County websites.

Interstate 70 between Glenwood Springs and Gypsum remains closed, as it has been all week, as transportation officials tell drivers to use planned detours and not rough mountain passes.