From late February to early April, and again in the fall, one can easily watch — and hear — a huge, distinctive bird, the greater sandhill crane, as flocks stop to rest, en route from winter homes in New Mexico to nesting sites in northern Yellowstone and along Wyoming's northern border, and again during the return flight in September ...

Colorado's San Luis Valley and an area along the Yampa River both serve as a refuge for these four-foot-tall birds with a six-foot wingspan, as they call back and forth to each other.

Members of my family look forward to an annual mid-March trek to Monte Vista to watch and listen for a few days ... Rites of spring!

And once you've seen a flock of these flying fossils take flight in the early evening, against an orange sky — still calling to the others — you'll never forget it.

Nor will others, who write ...

Colorado naturalist Mary Taylor Gray, who lives in Castle Rock, says in her book, “Guide to Colorado Birds”: “The passage of up to 20,000 sandhill cranes through the San Luis Valley in mid to late March is a stunning sight not to be missed. The fields around Monte Vista and the wet meadows of the Monte Vista and Alamosa National Wildlife Refuges fill with four-foot-tall birds, all calling loudly. Here and there birds bow and leap, fan their wings and prance around as part of an elaborate courtship dance ... the air fills with their raucous calls, which merge into a kind of trilling when many birds are calling ... The sight of dozens of sandhill cranes feeding in a stubble field seems like a scene from another epoch ...”

Famous conservationist/writer Aldo Leopold commented: “Our appreciation for the crane grows with the slow encroachment of earthly history. His tribe, we now know, stems out of the remote Eocene. He is the symbol of our untamed past with that incredible sweep of the millennia that underlies and conditions the daily affairs ...”

Somewhere in the San Luis Valley, there is 5,000-year-old rock art that shows a flock of cranes in flight — just as a visitor sees them today.

And, there's an ancient cottonwood tree where a great horned owl is sitting on a nest ...

The wildlife refuge is planned with cranes in mind — wetlands where they can forage for small water creatures and nearby fields where farmers leave a goodly portion of barley and wheat after they harvest. One sees thousands of birds in the morning — until about 10, when they fly away to good places to eat through the day. They return to several sites near the refuge about 4 p.m. and forage — and call and dance until sunset, when groups begin to take to the air, still communicating in that ancient language, as they leave to roost in water for the night.

Next morning, same routine — they need to store up multiple calories for the next long flight north, where pairs — mated for life — will nest and raise one, or possibly two chicks who will accompany them back south in the fall. They keep the offspring with them for about a year, so a visitor will notice smaller brownish adolescent birds hovering near a pair — not ready to mate for another year or two.

One wonders how to spell the sound of that call — is it “kraaak? kraall? krooll?” (all with a definite rhythm and the combined trilling effect Gray describes).

It's about a four-hour drive on U.S. 285 from the Denver area, past South Park, Fairplay and Buena Vista, catching your breath at the sight of Collegiate Range to the west, while the Arkansas River rushes past just east of the highway. With warmer weather, hundreds of rafters will splash through Brown's Canyon, named a national monument in 2015 by President Obama. (One can pull in, park and hike there.)

Our group stretched it into a two-day drive, with a stop at Cottonwood Canyon Hot Springs for the night, a soak and a nice dinner in Buena Vista. And, since there was a birthday to celebrate, a next-day stop at Sunflour Bakery and Café, on the highway into Monte Vista — for lunch and “birthday pie.” (Hours are limited to breakfast and lunch, and that pie is really special!)

We checked in at a family favorite: the Movie Manor Inn, decorated throughout with scenes from memorable films and names of actors ... My offspring, now 60-ish, remember watching movies from our beds during summer trips, which are still in operation in warm weather, but not now.

Finally, it's time to drive south on Highway 15 to the Monte Vista National Wildlife Refuge and adjacent fields, where birds fly in for a late afternoon meal. (Teatime?) From about 4 p.m. to 6 or 7 p.m., thousands of these birds fly in calling, land with feet forward and begin to munch, interspersed by some with those distinctive dance moves and more calls. They feed for a couple of hours, then it's time to go to a roosting spot for the night. By standing in water, they are less vulnerable to predators, such as coyotes.

With morning comes a repeat of routine — for cranes and birders ... In a month or so, cranes will fly north, but they can be observed again in mid-September — also an especially pleasant time for travel in Colorado.

Enjoy.