Mike Schwitters calls it a spectacle of nature.

The annual snow geese migration at Freezeout Lake Wildlife Management Area north of Fairfield is certainly that. Straight out of an episode of “Planet Earth,” the congregation of tens of thousands of snow geese along the Rocky Mountain Front is a staggering sight to behold.

Schwitters, of Choteau, establishes the snow geese estimates reported on the WMA's waterfowl migration hotline. He's has been keeping track of the migration since the 1980s.

“There was a time when I would count 100 geese. Then I would count another 100 and come up with what appeared to be 1,000 birds,” Schwitters, 74, said Monday. “Once I had that in my head, I can drive up to a flock of 20,000 white geese and I count how many thousands there are based on what a thousand white geese looks like.”

Snow geese stop at Freezeout Lake during their annual migration from winter habitat in California to nesting grounds in the Canadian, Alaskan and Russian Artic. Schwitters said he’s seen as many as 300,000 white geese on the WMA at a single time. His observations indicate the migration typically peaks on or around March 28.

Mark Schlepp is the FWP wildlife manager who reports Schwitters' estimates on the hotline. On Tuesday, the number of geese using the WMA jumped from 30,000 to 40,000.

“I think we are 10 days into the migration period that should last three or four weeks,” Schlepp said Monday. “Numbers have slowly built up to this level … but I don't think we have seen the majority of the birds pass through.”

Schlepp said Freezeout Lake presents an oasis for snow geese and other waterfowl species traveling north.

“Freezeout is a waterfowl motel,” Schlepp said. “It has a pool and a good restaurant.”

Freezeout Lake WMA includes the main lake and six smaller ponds. The Priest Butte Lakes two miles to the north also provide open water for geese to congregate.

To the east of Freezeout is the Fairfield Bench. Fairfield is the self-proclaimed “Malting Barley Capital of the World.” Geese feed on waste grain in the fields, flying out in the morning near dawn, returning to Freezeout mid-day, and flying out once again in the afternoon.

Snow geese stay at Freezeout Lake an average of 4¼ days. Schlepp said after flying 18 hours from California, the geese need to rest and refuel for the push north.

There are around 15 miles of predominantly gravel roads in the WMA. Birders can drive around the ponds to different viewing areas and pullouts. The birds are generally tolerant of human presence during the spring migration.

The most thrilling experience for many birders is witnessing a big fly out when thousands upon thousands of geese take flight and head east to the fields or north to the Arctic.

“Snow geese are very vocal,” Schlepp said. “When you are watching birds on the water or feeding, you can notice a change in their vocalization. They get a bit noisier and the octave raises and you will see that big whoosh when they take off. The whole mass can take off in a big cloud of birds.

“At the tail end of the season and I can go out on my deck and there is just wave after wave of those birds moving on,” Schlepp said. “It is hard to imagine the numbers that are there and how noisy they are.”

Schlepp said this year's snow geese migration is proceeding slightly ahead of schedule, though winter weather could slow the migration.

“The geese are pushed by their biological clocks,” Schlepp said. “They still have a long way to got to their nesting areas. It can be over and done with quick. If you want to see them, you better come now.”

Ben Pierce can be reached at bpierce@dailychronicle.com and 582-2625.