GEOFF BENNETT: This past winter was an extraordinarily dry one in the western part of the country.

A lack of snowpack that normally feeds the Colorado River has only deepened the impact of a wider drought out West, which affects tens of millions of people in seven states and Mexico.

And, this spring and summer, that drought made worse by climate change is taking a big bite out of farmers' plans in Colorado.

Our science correspondent, Miles O'Brien, has this report for our series Tipping Point.

MILES O'BRIEN: Hugh.

HUGH SANBURG, Colorado Rancher: Miles.

MILES O'BRIEN: Thanks for meeting us.

I met cattle rancher Hugh Sanburg at the gates to his property in Delta County, Western Colorado.

With Diva (ph), the diligent dog riding shotgun, he drove me up a hill to survey his pastures.

The scenery here is as rare as the rain, only about 12 inches a year.

And the brown patch tells the story.

HUGH SANBURG: We won't have enough to feed all the cows we have without either buying some hay or selling some cows.

MILES O'BRIEN: He'd rather not go into debt at this stage of his life, so he is now counting cows, seeing which ones he will cull.

Ranchers and farmers here depend on a century-old labyrinth of creeks, ditches, and diversions to keep their fields green.

This year, he's receiving only half the water he normally counts on, even though his water rights date back to 1896, placing him near the top of Colorado's seniority system.

So you have senior rights, but in the face of whatever's going on with the weather, it doesn't add up to much, does it?

HUGH SANBURG: Well, you have you have got to have water in the stream to make water to come down the ditches, and, unfortunately, we don't have water in the streams this year.

MILES O'BRIEN: These are the headwaters of the Colorado River.

The water in these streams starts as snow high in the mountains that surround the valley.

But this year, nature came up short.

A drier, warmer winter was followed by an exceptionally hot march, triggering an early melt.

By May, about 70 percent of the snowpack had already disappeared.

JASON ULLMANN, State Engineer, Colorado Division of Water Resources: Our biggest reservoir in Colorado is the snowpack.

This year was shocking.

MILES O'BRIEN: Jason Ullmann is the state engineer.

He is responsible for managing one of Colorado's most precious resources water.

He took me on a tour of the Uncompahgre River Valley, a tributary of the Colorado.

How would you characterize that river relative to other springs?

JASON ULLMANN: So we would expect there to be hundreds of cubic feet per second here.

This is approximately four CFS, so very low for this time of year.

MILES O'BRIEN: The stream flows dwindling, Ullmann and his team face an unenviable task, shutting off water deliveries to the valley's 85,000 acres of irrigated farmland based on seniority.

Not far from Hugh Sanburg's ranch, Chan Fogg tends a 60-acre orchard, nearly 30,000 apple, pear, and peach trees.

CHAN FOGG, Colorado Orchardist: Everything that we do, we have to have snowpack.

And without snowpack, we have a drought.

Instead of bins of apples this year, we will have pounds of apples.

MILES O'BRIEN: He says it takes about 30 inches of water to produce a healthy, profitable crop; 20 inches is the bare minimum just to keep the trees alive.

CHAN FOGG: We don't have a choice of not irrigating, because, if you don't irrigate, the trees die and you have lost your lifetime investment.

MILES O'BRIEN: So this is all apples?

CHAN FOGG: This -- well, this is peaches on this side and apples over here.

MILES O'BRIEN: I got you.

Chan Fogg has worked hard to get by with less water.

He showed me his ingenious system.

CHAN FOGG: This is the ditch that supplies our water, Chiles (ph) Ditch, and it comes in here.

MILES O'BRIEN: Water travels through a buried pipe to a pump system that Isaac Newton would appreciate.

Gravity does all the work.

CHAN FOGG: This gauge over here is a flow meter, and it shows that we're using 168 gallons a minute right now.

MILES O'BRIEN: The pumps feed a micro-sprinkler irrigation system.

He installed it a decade ago, thanks to some federal grant money.

CHAN FOGG: It's just a lot more efficient, and you get the same amount of water from the from the top of the orchard to the bottom.

MILES O'BRIEN: And do you use less water with it?

CHAN FOGG: Oh, considerably less, yes, probably less than a third as much water.

MILES O'BRIEN: All right, let's go see how you irrigate all these things, huh?

It's not enough to erase his worries.

But this spring's wild weather may have offered Chan one small silver lining.

The March heat wave brought his fruit trees into bloom weeks early.

Then came a hard freeze in April, wiping out his nascent fruit.

Crop insurance softened the financial blow.

And, ironically, fruitless trees need far less water.

CHAN FOGG: The trees will get stressed, but they won't -- if we just keep a minimal amount of water on them, they will make it through the year.

MILES O'BRIEN: Fogg and other farmers here are able to purchase water from a string of small reservoirs in the mountains nearby.

But they provide a cushion for only one dry year.

JASON ULLMANN: If we have another year after this year like this year, it's going to be a lot more painful than it is even this year.

They will just be completely off.

MILES O'BRIEN: With so little water stored for not-so-rainy days, farmers here are accustomed to shortages and curtailments.

REID FISHERING, Colorado Farmer: With our water situation, we have had to fallow pretty much half of all the fields that we have.

MILES O'BRIEN: Reid Fishering grows sweet corn in Delta County.

As we walked his farm, he showed me the stark line between the fields he was able to plant and those he was forced to leave fallow.

REID FISHERING: This shows the demarcation line of possible money versus us having to just sit fallow and not make any money on it.

So this kind of represents our economic outlook for 2026.

MILES O'BRIEN: In a normal year, Fishering plants about 1,000 acres.

This year, it's closer to 500.

What we saw on the Western Slope of Colorado is just one small part of how the 25-year drought fueled by climate change has affected the entire Colorado River system.

Lakes Mead and Powell, two giant reservoirs downstream that provide water to California, Arizona, Nevada, tribal nations, and Mexico, are at critically low levels.

REID FISHERING: Every single year, we seem to be hit by something new, and this is -- This almost feels like this hopefully is not the last nail in the coffin, but it has the looks of it, for sure.

MILES O'BRIEN: This bone-dry growing season comes as the seven Colorado River Basin states struggle to negotiate a new agreement on how to share a shrinking river.

As they debate the size of the cuts and who should bear them, nature has weighed in with a reminder: It always bats last.

For the "PBS News Hour," I'm Miles O'Brien in the Uncompahgre River Valley, Colorado.