We spent a restless night, my sister and I, in a tent in Oak Creek Canyon. The wind roared unceasingly above us, the proverbial train tearing by. We lay silently in our sleeping bags each thinking the other was asleep, but in truth we were both convinced we'd die in the night, crushed by a falling tree. 

Yet neither of us gave a thought to fleeing to the relative safety of her car. Camping at Oak Creek meant too much to both of us: To my sister, who spent the happiest days of her childhood here, and to me, who was seeing it for the first time.  Images of her (and my) siblings were everywhere she looked – running, swimming, fishing, climbing, while I was lying under the very trees and red rocky cliffs where my mother once slept. The mother I'd never met. 

We were up at first light, which in a canyon can be well after sunrise, admitting to each other that it was a miracle we'd survived. Yet studying the trees that loomed over our site we admitted we'd probably been in no danger; the Ponderosa pines we'd slept under were wind-tossed only at their very tops as the canyon walls had protected us from the gusts. Yes, my mother would have seen these trees 60 years ago. 

This sister and I have known one another for 27 years, the year her middle child was born. I'd just seen my own first-born off to college. The 18-year search for my birth family, which began the day I held that baby for the first time, had finally ended.  

I'd learned that the woman who gave birth and "surrendered" — wherever did that word come from? — me to be adopted, had died in 1965 at the age of 42, the year I was 21.  

After my birth she completed nurse training in South Bend, Indiana, her hometown, and that spring got on a plane to Pasadena. There she met the man she'd marry, move to Phoenix and have five more babies; she, a woman with a rheumatic heart from childhood scarlet fever. A woman who'd been warned against any pregnancies at all.  

That damaged heart caught up with her the year my sister was 12. She died leaving my five half-siblings, ages 5 through 17, to grow up without her. When their father died a few years later, they were all truly on their own. 

I, her first-born, though, found myself on a different path. My 21-year-old mother, at the suggestion of the doctor who'd confirmed her pregnancy, made arrangements to have me adopted through an agency in Evanston, Illinois. I was 9 weeks old when I went home with my new parents. 

My life from then on held no drama. A mom and a dad, and a couple of years later a surprise baby boy born to them, my brother, and our family was complete. There were no illnesses or untimely deaths or abandonments in our future. It was indeed the kind of childhood I'd wish for everyone. 

Why, some wonder, do adopted people need to search out their birth families? Or, more exactly, why do some have that need? I only know that I did. 

I love to tell the story of how I found mine, and if you're curious, ask me. It's too long to write here. 

So my sister, whose memories of our mother are those of a 12-year-old, and I decided to finally go on a road trip together, to find her, the woman who gave birth to both of us.  

I should add here that we long ago bonded, she and I, that she's spent weeks and weeks with Wally and I in Maine, that we've visited her in New Orleans, her home, that we've traveled to Indiana together and found our ancestral roots. We speak on the phone regularly. She and I are truly sisters. 

A couple of weeks ago we drove away from her Louisiana house in a car packed full of camping gear and headed across Texas along a route our mother took at the end. Heart surgery in Houston, a drive to Phoenix where the family was living, and where she died soon after.  

"I want you to see where I grew up," my sister said, and as we drove from the lush, green and water-filled world of Louisiana across the increasingly arid plains of Texas I began to see. But it wasn't until we hit the Arizona desert that she truly was home.

"This is where I feel comfortable; this is what I love," she told me. 

We packed a lot into this road trip. "Let's stay flexible," we decided and see where it takes us.  

There was still a sibling I'd never met, our mother's youngest daughter. Now I have. I couldn't take my eyes off her across the table at dinner in Phoenix. There's no explaining it. I studied her eyes, her hair, her mannerisms. And you don't want to stare, to be weird about it. But the adopted need to see themselves in these other faces.  

We had an unexpected two days in Mexico with my sister's daughter, a niece I'd never met. Again, that surreptitious studying of features, of voice, of personality. Do I see my own boys in her, their first cousin? 

My sister and I have developed a narrative, a story about who our mother was, why she lived her life as she did. We've pieced it together from the facts of her life that we've learned from our other siblings and from older relatives. We imagine that someday we'll write it all down, along with the way our own lives have unfolded, starting with the same mother. 

One more thing. Arizona. We seem to hear a lot about Arizona back in Maine. People winter there, move there. What is it about these two, somebody wondered the other day, that people have an affinity for such a cold, wet place and a hot, dry place as Maine and Arizona? 

Along the way we've visited Carolyn Marsh, a longtime Camden friend, at her Bisbee mountaintop house, and at the end of our trip, Judith Butterman in Rio Rancho, New Mexico. OK, it's not Arizona but in my mind, the same. 

The Buttermans lived at Lincolnville Beach in the 1970s, across from Green Tree Coffee where Andy Young lives now. We raised animals with them, steers and pigs, learned to butcher them and ate many meals together. Judith and I have stayed in touch through the years, and she's occasionally visited us. 

Now it was my turn to visit her along with her son, Jonathan and daughter Jennifer; their brother, Craig lives in Rio Rancho, as well. We got a tour of the house Jonathan and his wife, Dee, have just finished on a hillside in Placitas and even spotted the wild horses that roam nearby. 

Other Lincolnville folks we missed seeing, but had been in touch with, are Brad and Linda Knight, who've settled near Tucson, and Steve and Jane Hardy, who winter in Phoenix.  

My head is full of desert images: stony, arid, flat, then craggy and mountainous. Southern desert with its Joshua trees,those tall, iconic saguaro cactus as far as the eye can see, then turns to the northern desert, barren with high mesas and the improbable, impossible Grand Canyon. 

Finally, Oak Creek Canyon where I know for sure my mother looked at the same red cliffs I saw.