We hit some wicked cross-winds with driving snow at Teton Pass. Sharp curves, steep grades—I was having a blast. Bob Seger was in the CD player, Running Against the Wind, and every couple of minutes James would look up from his Nintendo, look out the window and shout, "Whoa, Nellie!"

It didn't turn into a blizzard until we hit the south entrance to Yellowstone. The Park Ranger warned me that the roads to the West and the North were closing; we wouldn't make it to Old Faithful tonight. But I had the power of a pair of Alaska license plates on a four wheel drive pickup, so she waved me on through. I also had a teenaged son in the truck with me, ready to offer driving advice.

"Mom, shouldn't we be driving slower on this road? LOTS slower? I think the speed limit's thirty."

"You can't hesitate during a blizzard, son. That's the key. Just forge ahead with confidence, get your momentum going. You keep a watch for wildlife."

The forest was dense and dark, pushing at the edges of the slick road. The fir trees were already holding a load of snow in their branches.

"I'll let you know if I see a pullout."

"We don't need a pullout. We're not turning around."

"Just in case you need to pause, Mom."

"Son..." I didn't know how to explain. Pausing is dangerous. You pause, you lose your nerve. You lose your nerve, show some fear, a bit of weakness, life will go for your throat. I knew this was true, but I didn't know how to tell him.

The sleeping bags in the back of the truck were being buried in a drifting snow. This Yellowstone wind was going to snatch up our little tent and turn it into a kite, if I was fool enough to try and set it up.

"Have you heard this before, son? It's from a Wintu dream song: Where will you and I sleep? At the down-turned jagged rim of the sky you and I will sleep."

"Okay, Mom. Or we could just find a hotel." He gave me a gentle pat on the knee. "I'll help you look."

Sarah Black is a fiction writer living in the American West. She spends her free time dragging her son and a couple of sleeping bags around our National Parks.