Years ago, three of them, I was in a small Mexican village by a lake and a dam where mustachioed fathers in sombreros park their trucks at the gate and silently follow their exhilarated children down the grassy path to the fishing hole. I was there for a month and a half. Longer than a visit, shorter than a move. Supposedly I was researching relationship networks between sending and receiving communities of immigrants.

There were two young girls in the house where I stayed: Fernanda and Paola, ages 6 and 4. Each morning around 7 I awoke to Fernanda cranking up the volume and bass of the stereo in my room. Los Angeles Azules, a cumbia band that continues to fill me with honeyed nostalgia, blared out of the speakers while Fernanda crawled onto the bed and started jumping up and down: “levantate guero! levantate!!” Paola, the soft-spoken sister, would be peeking around the doorway with big eyes and an embarrassed smile. Fernanda waves her over: “ven Pao!” and they’d both jump up and down, up and down on the old, mushy mattress until I turned into the big guero cosquillas monstruo and tickled them until they threatened to hacer pee pee in my bed.

About half an hour later I would sleepily walk down to the neighborhood panadería with the girls while their grandmother, Maria Elena, made us coffee and huevos revueltos. One morning the girls were even more hyperactive than usual. As I spooned sugar into my muddy coffee, avoiding the red ants that inevitably made their way inside, Fernanda hit me on the arm:

– “Que crees gringo?”
– “Fer!!! No le digas ‘gringo’! Ai, eres una niña tremenda,” scolded her abuela from the stove.
– “Gringo, vamos a ver las maripositas!!”

Paola had chimed in on the last word as she was prone to do … the constant punctuation mark on her older sister’s confidence.

Monarchs go through four separate life stages. They begin as an egg, hatch as larva or caterpillar, become pupa (chrysalis), and mature into adult butterflies. The eggs hatch in small batches of five to ten, depending on the ambient temperature. The caterpillars devour their eggshells and begin the quest for food, feeding exclusively on the milkweed family. Each time they outgrow their exterior skin (called a cuticle), they molt, eat the skin, and continue growing. After four cycles of molting, they attach themselves to the underside of a leaf and form a delicate and beautiful chrysalis. Inside the chrysalis, a developing butterfly matures for several weeks. When it’s time to break loose, the insect pushes its legs downward, splits the chrysalis and sets itself free. The newly hatched butterfly pumps the fluid concentrated in its body into its wings, which then harden, allowing it to fly.

The butterflies of Sierra Chincua, or Chincua Hill, are monarchs. The flitting, orange-yellow-and-black insects found over much of the United States during summer months. In winter, nearly all North American members of the species congregate in a tiny region of Michoacan.

Each September, 100 million or more young monarchs begin the journey south. A couple of months and several thousand miles later, they home in on central Michoacan’s oyamel forests. Here they and their progeny stay all winter, moving only slightly to change elevation as temperatures change.

In late February, the monarchs display a burst of reproductive passion. Impregnated females then depart for the north. The males die here.

Scientists believe that the monarchs have been repeating this cycle—and making their annual pilgrimage to Sierra Chincua and a handful of neighboring hills—for thousands of years.

The miracle of the monarchs’ migration lies not only in the distance that the fragile animals cover, but also in the fact that no single butterfly knows the way from experience. Their lives span only a few months each, so the individuals that make the journey to Mexico are several generations removed from those who last left it.

Just over three years later – far removed from the graduate student life I had envisioned – and here I am driving north on the 505 freeway which connects Bay Area’s I-80 with the Interstate 5. We were in San Francisco for a week, staying with the grandparents, finding Booger a place to live, visiting friends, and relishing the cool temperatures and tasty food.

Booger is in the passenger seat sleeping, it’s what she does best. On the iPod Joni Mitchell and Van Morrison take turns.

First there is just a glimpse, an unsure occurrence, a blurred fluttering of yellow bobbing up and down across the freeway, weaving between the SUV boxes of steel that hum along at 80 mph. Then a couple, a few, a few dozen. It becomes obvious that we are at a crossing point between nature’s most mysterious migration and man’s most aggressive, most individualistic method of transportation. And it is obvious who will lose.

Left and write the yellow, velvety butterflies explode in mustard-like stains across the windshield. Around Road 19 (which, it should be pointed out, is also Exit 24), and the maelstrom of fluttering wings is so thick it is like cutting through sepia-colored fog.

The pavement is blanketed in massacred mustard, like chips of margarine waiting to be spread on toast.

No, they were not monarchs, not ancestors of the same butterflies I saw in Michoacán. But still, I knew that there was a story behind their journey: either a championed existence that met its fate on an unimportant freeway or a youth full of optimism which was never able to flower.

And, no, I still don’t believe in destiny. But, as Joni Mitchell sang A Case of You, it was entirely too tempting to think back on all of the directions turned, the choices made, the stalling hesitations, and the tragic timeliness that led to my cataclysmic encounter with those mariposas.