The sound begins like a distant jet roar, approaching us through the thick stand of Douglas fir, a low rumbling growing louder in intensity. I look at my friend Erick. He looks at me.

“Avalanche!” we say in unison. But we don’t move.

We are safe, a mile or so from the steep 10,000-foot peak that is unleashing a torrent of snow and rock with the rising temperatures. The sound continues to carry, then rumbles away like thunder. We re-mount our bicycles and continue pushing our wheels down the pavement of the Going-to-the-Sun Road, following the yellow-striped line into the heart of Glacier National Park.

Weather forecasts are calling for 70-plus degree temperatures later in the day, but the morning air is cool, especially in those pockets of forest that trap the cold morning air. I’m partaking in a favorite spring ritual, biking on the historic Sun Road after plows have pushed the deep, lingering snow off the storied pavement, and automobiles are blocked from passage by a simple, brown, metal gate and a sign -- currently at Avalanche Campground: “Road Open for Hiking and Biking.”

Enjoy it while you can!