But her long driveway was blocked by mountains of mud — impassable even for an ambulance or a tractor.

So Red Cloud-Yellow Horse, 59, set off toward the road on foot. She fell repeatedly, almost got swept away in the current of a creek, and became stuck in the mud. Finally, more than an hour later, she made it the half-mile to the highway where she was picked up.

Such stories are startlingly common these days on the Pine Ridge Indian Reservation in South Dakota as an overwhelming bout of snow and flooding has set off a humanitarian disaster that seems unlikely to abate soon.

With some residents approaching two weeks stranded in their homes, and with emergency rations able to reach parts of the back country only by horse, boat and helicopter, Pine Ridge remains in a state of shock and triage.

Officials with the Oglala Sioux Tribe, which administers the reservation, say they lack the training, manpower and equipment needed to deal with such a large-scale crisis. And there’s a pervasive sense on Pine Ridge, a place of long-strained relations with the state and federal governments, that help has been woefully slow to arrive, and that few people beyond the reservation know or care much about its plight.

Pine Ridge was far from alone in being hit with damaging quantities of snow and water this month. Huge portions of the Midwest were swallowed by rivers in the past 10 days, and the affected states have estimated that they have suffered more than $1 billion in damage and economic harm.

Outside help for Pine Ridge, with a population of about 20,000, was conspicuously scarce at first. South Dakota Gov. Kristi Noem has been seen by many Pine Ridge officials and residents as slow to respond. But Noem, who visited the reservation Saturday, said that the tribe had only made formal requests for help in recent days, which she quickly approved. Since then, Noem said the state had sent ATVs, a boat rescue team and a small group of National Guard soldiers to distribute drinking water.