My passport had expired.

Apparently, it had run out back in May but I hadn’t noticed, not having had any need to since I last crossed the border back in 2017. But now, with a customs officer checking it at the Montana border, I found out, much to my dismay, the passport was no longer valid.

Fortunately, he very courteously told me not to worry. The officers have the discretion to allow entry up to six months after a passport has expired. Kindly, he let me cross.

I was headed down there for two reasons. First off, I love Montana. It’s gorgeous — essentially an extension of southern Alberta — and the people are kind and welcoming. But second, and more importantly, I was concerned about the catastrophically low flow of the Milk River.

I’d seen first-hand how low the water was at the Writing-On-Stone Rodeo back at the beginning of August. This dream of a rodeo arena sits among sandstone cliffs and is embraced by a curve of the undulating Milk River. The rodeo itself is great but one of the things I like best about it is watching the kids and horses splashing in the silty waters of the river.

This year, though, there was very little to splash in. In fact, the river was at its lowest level in nearly a century.

OK, this is going to need a little explaining.

The Milk River is unique in Alberta in that it is not part of the Saskatchewan River system. Instead, its waters flow into the Missouri River and then on to the Mississippi River before hitting the Gulf of Mexico. You could technically get in a canoe at Writing-On-Stone and then paddle all the way to New Orleans.

Glacier National Park in Montana holds the headwaters of the river but it then flows north across the border and through southern Alberta before entering Montana again near the Saskatchewan border. Its fluvial neighbour, the St. Mary River, also starts in Montana and then flows north across the border into Alberta. The difference is that the St. Mary, thanks to a low ridge between the two watersheds, flows into the Saskatchewan River system which then empties into Hudson Bay.

The two river systems are maybe 20 kilometres apart but they flow in opposite directions.

As they have for millennia. But in the 1920s, a group on the Montana side figured they were losing out on the water that flowed north into Alberta so they devised a scheme where they would take a portion of the flow of the St. Mary River and divert it into the Milk River. That way they could get back some of the water they “lost” to Alberta.

To do that, they built a weir just south of the border that channels St. Mary River water into a canal that runs into a huge set of siphon pipes that carries the flow to the North Fork of the Milk River. From there, it runs downstream through southern Alberta and brings extra water to American farming and ranching outfits back on the Montana portion of the river. Work on the canal and siphon was finished in 1924 and the water has flowed........

© Calgary Herald