Snow Closed the Highways. GPS Mapped a Harrowing Detour in the Sierra Nevada.

Stagecoaches used to travel through the national forest and the Sierra Nevada on the road that was once used during the Gold Rush.

The Quincy-La Porte Road is closed in the winter.

Wendy Becktold, an editor from the Bay Area who was on her way to visit an ailing relative in Reno, Nevada, on Monday, said that she had been unaware of that when she drove her rented car onto the road.

She said in an interview on Wednesday that she had been guided that way by the help of the internet, and that she was worried about the potential dangers of using too much of a gps application.

They said that the mapping programs, which are owned by the company, wouldn't always account for seasonal road closings.

There were many cars behind us. Everyone was routed the same way.

Ms. Becktold, a senior story editor for Sierra, a magazine published by the Sierra Club, said that she and her cousin had seen a tree limb on a power line and had passed many cabins as they inadvertently pressed on. They put chains on their tires. Ms. Becktold said that a worker in a safety vest waved them off.

Ms. Becktold said that he told them to just show him their phones. He was like frustrated.

A spokeswoman for the tech company said in a statement on Wednesday that it was taking steps to provide accurate route information.

The spokeswoman said that the team was working as quickly as possible to update routes in the Lake Tahoe area using details from local authorities. We show a winter storm warning to alert drivers in the area, and encourage everyone to stay alert and attentive.

There are no warnings about winter road closings or unpaved roads on the maps. The detours were reported by SFGate.com.

Raymond De Guzman of Hayward, Calif., removed snow chains from his tires on Tuesday as his daughters shivered nearby. The family decided to turn back after the traffic on Highway 50 was slowed by the heavy snow. Credit...Randall Benton.

A family of five from Southern California were stuck in the snow for two hours on a two-lane dirt road in Washoe County, Nevada.

The family wanted an alternate route to go to visit relatives in Truckee, Calif., during the storm, which closed an 81-mile stretch of I-80.

According to the Central Sierra Snow Lab at the University of California, Berkeley, more than 17 feet of snow had fallen by Thursday. Highway 50 was closed for about 50 miles in the Sacramento Valley and the Lake Tahoe Basin before I-80 reopened.

The family ignored the warnings and used the Dog Valley-Henness Pass roads.

The sheriff's office said in a post on Tuesday that the family had been rescued and that the family's gps won the battle of which technology to listen to.

The family had been using a gps application.

The Washoe County Sheriff's Office said in a public warning last week that drivers had taken the same detour many times. Emergency responders were called to 11 rescues over the course of a year.

Caltrans tried to reinforce that over reliance on gps apps could be risky, according to an email from a spokeswoman.

When people try to use mapping apps to avoid highway closings, they can sometimes be put in dangerous situations with unplowed roads and no cellphone service. People are always told to stay on highways and find alternate routes. We recommend that people stay put until the highway is reopened.

The Sierra County Historical Society describes the Henness Pass Road as a secluded and winding mountain road that rises to an elevation of 6,920 feet. The historical society describes the road as a primary emigrant trail from Virginia City, Nevada.

The detour is about 40 miles away from the Donner Pass, which was named after the doomed pioneer family who used to cannibalism.

The company is committed to helping drivers navigate efficiently and safely, according to an email from a spokeswoman.

The spokeswoman for the community map editors said that they keep their maps updated with the latest real-time information. Drivers are encouraged to stay alert on the road.

Drivers can use the filter on Waze to avoid unpaved roads.

Crystal A. Kolden, a geography and disaster scientist at the University of California, Merced, said she was shocked when she saw that Henness Pass and other backcountry roads were suggested by the search engine.

Professor Kolden said that they are barely drivable in the summer. How reliable are these companies?

Professor Kolden was at her home in Sonora, Calif., in the foothills of the Sierra during the storm, and she criticized the maps on the internet. Some commenters said that drivers should take responsibility for monitoring conditions and that she sounded like a young person.

She said in an interview that blaming vulnerable people for going down the wrong road is the same as blaming poor people who drowned in their basement apartments in New York City.

On Wednesday, the red dots on the road that Ms. Becktold had traveled on on Monday were shown on the map. She said that the road closure warnings hadn't been there before.

Ms. Becktold said that they were looking for a day in the snow.

Ms. Becktold had to return to Berkeley when she was about 150 miles into the trip. She said that her cousin flew from San Francisco to Reno through Los Angeles to reach her brother.

She said that it was silly that there was no clear information online about the closed roads.