In February 1998 while driving in Arivaca's rugged back country, Tilda Martinez suffered a severe fright that changed her life.
"I was driving behind my husband and one of our daughters when he suddenly he took off down the side of the hill."
By the time he stopped she was trying to reach him and angrily asked what was he doing.
"My brakes went out," he told her.
She said she suddenly realized how vulnerable they were.
"I thought if one or both had been hurt really bad, it would take a long time to get help."
It can take an ambulance 45 minutes to for an ambulance to respond to an emergency call, 35 for a helicopter.
The realization spurred her to action.
"I wanted to do something to help the others here," she said.
She joined the Arivaca Volunteer Fire Department as an EMT--emergency medical technician.
Earlier this month, the board of the volunteer department named her chief.
She's one of three female chiefs in Arizona. And there are fewer than 200 female chiefs throughout the United States.
She said recently she was talking to a dispatcher somewhere in Pima County and identified herself by her old badge number, No. 1228.
"No, you're No. 1201," he told her.
That sort of surprised her. She said to herself, "I guess I am 1201, chief," she said.
The department is all-volunteer. It has about 18 members.
There are seven vehicles including engines to fight structure fires, smaller ones for use on wildland blazes and a emergency response vehicle, an ambulance. Volunteer mechanics keep them running.
The department services 452 square miles protecting areas from Arivaca to Sasabe.
The professional fire crew at the Buenos Aires National Wildlife Refuge west of Arivaca sometimes helps out.
"They are a valuable resources," said Chief Martinez.
The help goes both ways, Arivaca Fire helps the Buenos Aires.
Arivaca Fire got 206 calls last year, 80 to 90 for medical help.
It's a difficult area for communications. Generally they work, but there are some places cell phones don't work, ditto radios.
"You can feel awfully lonely if you need help and you're in an area where no one can hear you," said the chief.