The Murphy/Pajarita Fire near Rio Rico and Tubac has burned 50,122 acres and was 25 percent contained as of Monday night, said Bobby Matthews, a fire spokesman.
Burnout efforts to protect the Historic Atascosa Lookout were successful. Closures of Ruby Road will remain in effect.
The Pajarita Fire merged Monday with the larger Murphy Fire. Crews managed to keep the merged fire from moving into the Rio Rico area on Monday, officials said.
The Santa Cruz County Sheriff's Office issued a pre-evacuation notice for the elderly and people with special medical conditions to prepare in case they would need to evacuate.
Those notices were lifted later Monday, and no evacuations had been ordered as of Monday night.
A public meeting to discuss the fire is set for 7 tonight at Mountain View Elementary School, 580 Camino Lito Galindo in Rio Rico.
Horseshoe 2 Fire
Firefighters in Southeastern Arizona are strengthening containment lines on the north and northwest portions of the Horseshoe 2 Fire in Cochise County.
More than 104,000 acres, or 163 square miles, has burned since the fire started May 8. The wildfire has cost nearly $28 million to fight.
The U.S. Forest Service said crews are working to protect the community of Whitetail and Chiricahua National Monument.
Favorable weather conditions allowed firefighters to establish critical containment lines.
Officials said firefighters had contained 55 percent of the Horseshoe 2 wildfire.