ALBUQUERQUE, N.M. (AP) — New Mexico’s governor declared an emergency Thursday after a powerful winter storm left tens of thousands of people without power as heavy snow, fierce winds and freezing temperatures marched across the northern two-thirds of the state and into Colorado.

Dozens of crews with Public Service Co. of New Mexico were mobilized to address widespread outages that had been reported overnight and in the early morning hours from Albuquerque to Santa Fe and beyond as the snow brought tree branches crashing down onto power lines.

The utility acknowledged frustrations and urged residents to be patient, saying there were about 19,000 people still affected by the outages Thursday evening. That was down from 50,000 earlier in the day.

“This really is an unprecedented storm in the fact that it came so earlier and so heavily while leaves were still on the trees. That has caused limbs to be much heavier that they would normally be,” PNM spokesman Jeff Buell said, adding that crews were dealing with hundreds of separate repair jobs in Albuquerque alone.

With more snow in the forecast, Buell said there could be additional outages into Friday.

Gov. Michelle Lujan Grisham’s declaration unlocks state funding for emergency response efforts. Funding also will be funneled to the New Mexico National Guard, which has been helping to clear roads.

Schools in Santa Fe, Los Alamos and elsewhere across northern New Mexico canceled classes, while authorities warned people to stay off the roads. Plows were busy trying to keep major highways clear, but state police announced midday that Interstate 25 just south of the Colorado border was closed in both directions.

The National Weather Service in Albuquerque issued a blizzard warning for parts of the state and reported that more than 100 vehicles were stranded on highways in the state’s northeast corner. Forecasters warned of “very dangerous driving conditions” that were made worse by low visibility because of blowing snow.

Interstate 70 across Colorado’s Eastern Plains also was closed, as residents in that state braced for what some said could be the biggest snowstorm to hit the Denver area in November in years. Some people reported Thursday that they already had more than 14 inches (35.56 centimeters) of snow on the ground.

The National Weather Service Weather Prediction Center said extensive and widespread disruptions could be expected as the storm moves through New Mexico and Colorado, dropping between 1 and 2 inches of snow within an hour in some spots.

Tonja Goode Ross said she would be staying home and enjoying a cup of hot chocolate instead of trying to brave what was the “first real snow” of the season for Corona. This rural part of central New Mexico was turned into a winter wonderland, its pastures covered by a thick blanket of snow and its tree branches bowing from the weight of fresh powder.

Almost a foot of snow had fallen by early morning and another 2.5 inches fell within a 2-hour period.

“Moisture is always a blessing here — no matter the form it comes in,” she said.

The weather service warned that the storm could bring historic amounts of snow through Friday. More than 4 feet (1.22 meter) was expected in some parts. Snow drifts could top 6 feet (1.83 meter), making some travel impossible — potentially for days, forecasters said.

In Albuquerque, city officials said the frigid temperatures and snowfall resulted in about 120 traffic crashes while the fire department answered more than 100 calls related to downed power lines and fallen trees.