HAMILTON, Mont. -

Irrigation sprinklers are pumping full force in Western Montana. In the mornings and evenings, lone farmers walk their fields, shovels ready, flood irrigating their land.

The Bitterroot Irrigation District is the largest irrigation district in Ravalli County. They call it "The BRID." Old timers know it simply as "The Big Ditch."

Lake Como stores the water for the Bitterroot Irrigation District. It's from there, on that reservoir, that the 72 mile journey begins, from south of Hamilton to Eagle Watch near Florence.

Rod Sacks has been a ditch rider for 9 years. He's up at first light.

"It's a beautiful morning," said Sacks, as he drove this reporter, along his route, shortly after 7 a.m. "It's a little cloudy," said the ditch rider, "But you couldn't beat it."

Sacks is one of three ditch riders who patrol the winding canal.

Rod has the first 25 mile stretch. He opens 75 gates. He measures water levels. "I deliver water to our water customers," said Sacks. "I look for leaks."

At 102 years old, the irrigation system is showing its age. Steam shovels, draft horses and scores of men built "The Big Ditch" over four years.

The Bitterroot River divides the valley between east and west, and the old siphon that shepherds water across that divide into the Big Ditch is being repaired in phases.

But money is tight, and it's slow going.

Rod is constantly cleaning, fetching brush and debris that could clog arteries. He uses a long, type of pitchfork.

He turns a wheel that flushes a headgate along the route. "I clear out the trash," said Sacks, "because it's restricting the flow of water."

Farmer Bob Nicholson calls 'The Big Ditch' a lifeline. "We ran a dairy for 45 years," said Nicholson, "and without irrigation, we wouldn't have been here." Bob's dad was a ditch rider on the Big Ditch in 1924. Ditch riders back then rode horses on their routes.

A surge in population and demand for water have gone up over the years, as has the ditch rider's workload. "It's tougher because you've taken that same head of water and splitting it up maybe ten ways," said Rod Sacks.

The water Sacks delivers to clients is precious. But there's only so much of it. It got hot early. "Normally, we don't have this type of weather until June," said ditch manager John Crowley. "We're starting to lose a lot of snowpack.

Without irrigation, the valley is semi-arrid. Above the ditch, it's sagebrush. Below, if it's irrigated, it can be emerald.

Rod Sacks, the ditch rider knows. He's worked in agriculture his entire life. He's a native Bitterroot kid, who grew up on a ranch, and appreciates the farms on his route.

Seventeen-thousand acres owe their water to The Big Ditch. On an evening in May, the sprinklers dotting the landscape are picture postcard pretty, a sign of spring in the Bitterroot.