In the living room of a sprawling house on the edge of Sioux Falls, Mendel Alperowitz is winding a leather strap around the arm and fingers of Stuart Jacobs.

A box attached to the strap rests in Jacobs' elbow; inside is a scroll inscribed with seminal Jewish prayers that proclaim one God and profess man's duty to love that God. Another box rests on his forehead. They are performing the Jewish ritual of tefillin at Jacobs' home.

Alperowitz leads Jacobs in a prayer he once had memorized.

"V'ahavata. Et. Adonai. Elohecha. B'chol. L'vavcha," Alperowitz says and Jacobs repeats. "You shall love your God with all your heart."

When the prayer is over, Alperowitz takes out a ram's horn, a shofar, through which he blows a series of long and short blasts.

Jacobs, 55, takes it in with a wide grin.

"It always makes me feel better to do tefillin," Jacobs said, "because it takes me back to where I belong."

Jacobs, who was born and raised in the Bronx, is part of a tiny community of Sioux Falls Jews that has long gathered to pray and commune without a permanent rabbi. The last full-time spiritual leader of Mount Zion — the only synagogue in South Dakota east of the Black Hills — retired in 1978.

Lay leaders have picked up the slack, along with rabbinical students who fly in every other week from Hebrew Union College in Cincinnati. But some of the more observant felt something was lacking.

"I was starved for a leader," said Beverly Christensen, who has lived in South Dakota for 24 years.

Enter Mendel Alperowitz.

A clergyman without a congregation, Alperowitz moved to this city on the prairie to serve as a kind of Pied Piper for the Jews who don't have a spiritual home.

"My goal is that there should not be a single Jew in the state of South Dakota who feels that they don't have a way to express their Judaism," he said.

Although there are two synagogues and long established Jewish communities in South Dakota, Alperowitz has come for the isolated and the unaffiliated, whether they are devout or haven't prayed since childhood.

"No matter how far away they live from the Jewish community, however far across the state, we'll be there, we'll be visiting with them, in touch with them, doing Jewish things together," he said.

Since his arrival, the people who go to his classes or welcome him into their homes seem almost giddy to take part. Some have cried. Others have stopped him in public just to ask questions.

"I walk down the street, I'm a symbol of Judaism," he said, "whether I like it or not."

The 27-year-old has no intention of interfering with the state's synagogues, Mount Zion in Sioux Falls and Synagogue of the Hills in Rapid City. (While welcoming Alperowitz and his family, leaders from both synagogues say they've been self-sufficient long enough without a rabbi.)

But with most of South Dakota's Jews practicing a far more liberal strain of Judaism, or none at all, some of the state's Jews are asking whether Alperowitz is the rabbi South Dakota needs.

• • •

Alperowitz made a splash last fall when he announced his relocation to South Dakota from an insular and ultrareligious Jewish neighborhood of Crown Heights, in Brooklyn.

The story spread, in part because of its novelty: a deeply religious man with a frizzy red beard, who dresses in the black suit and fedora of the old world, moving to the prairie?

Alperowitz is a member of the Chabad Lubavitch sect of Hasidic Jews, who believe that every ritual performed by a Jew brings the Messiah a step closer. Like Mormons, Chabad rabbis take up posts around the world, establishing or enriching Jewish presence in far-flung places, from Nigeria to Nepal. By setting up houses for worship and gathering, Chabad managed to place at least one Jewish spiritual leader in every U.S. state.

Except one.

As an emissary of Chabad, Alperowitz visited Sioux Falls in 2016 to lead a celebration for the holiday of Purim. He sensed among some of the local Jews a thirst for a deeper connection to their religion.

"I don't have too many people like myself," Jacobs said. "It's been very difficult for me, difficult for my children. There was nobody to teach them Hebrew."

Alperowitz, a longtime resident of New York, also noticed a thirst in himself — a desire for open space, a yard for his two young girls to play in, and a mission.

When he returned to New York, he and his wife, Mussie, talked about what it would mean to move to a place with few amenities for people who follow strict Jewish dietary laws and pray three times daily. They would be giving up the village-like life in Crown Heights, where they lived among extended families. There would be no Jewish school for their children. They would have to drive four hours to Minneapolis to buy kosher meat.

Plus, money would be a concern. Alperowitz, whose post is funded through donations, will have to convince enough South Dakotans to support his work financially to keep him there.

"From a Jewish perspective, it's a whole lot easier and simpler in New York," Alperowitz said. "Will I miss that kosher sushi? I'm sure I will. But there is so much more meaning to what we're doing here than a piece of sushi."

In midsummer, the Alperowitzes left New York for a small Sioux Falls house with a grassy backyard, minutes from cornfields and cow pastures.

"The tundra is not as frozen anymore," said Mendel Feller, a Chabad rabbi in St. Paul.

• • •

Every Tuesday night, Pat Skewes drives an hour and a half each way from Marshall, Minn., to take Alperowitz's Torah study class, which he holds in the basement of his home.

Recently, a dozen attendees crammed around the table for a lively conversation about incrimination and justice. Some tried to stump Alperowitz on his interpretation of Jewish law.

The rabbi explained that there are some pleasures over which prayers are necessary, and some which aren't. Food, drink and aroma all have blessings.

"What about heat?" someone asked. "South Dakota is cold in the winter."

There is no blessing for heat, Alperowitz replied.

"If you lose heat and get it back," said another, "you thank God."

Skewes listened carefully.

Although she wasn't born Jewish, she has felt a pull toward the religion for two decades. In Marshall, there was no outlet for her curiosity. "I was very hungry," she said.

She prayed for a real opportunity to learn more about Judaism. Then, she heard the news about Alperowitz. "I wanted to say, 'Thank God, somebody knows I'm out here,' " she said.

She plans to continue to make the 180-mile round-trip drive, even when the roads turn icy.

"Every Tuesday night, it seems like no matter what he decides to teach upon, it's like life and fire in me," she said. "I have to be here."

Another Torah classmate, Beverly Christensen, felt completely cut off from other Jews in her rural community outside Sioux Falls. She started attending a church, believing that was the only way she could give her children a religious upbringing. When she saw a news story about Alperowitz moving to the state, she broke down.

"I sat in front of the television and I cried for hours," she said. "I got my religion back."

The Alperowitzes invited Christensen to a Shabbat dinner in their home. It was her first in 30 years. Following the multicourse kosher meal that Mussie prepared, they sat around the table and sang together. Christensen requested all the Jewish tunes she could remember — a folk song, prayers for holidays eight months away.

"It's like Mendel is here to find those of us who had been lost all of these years," she said.

• • •

Not everyone is thrilled to see Alperowitz's black fedora silhouetted against South Dakota's vast plains.

"Some people would say, 'He's not my rabbi, he doesn't represent me,' " because of the rigid way Alperowitz interprets Jewish law, said Steven Benn, president and lay religious leader of Synagogue of the Hills.

South Dakota's Jewish community dates back to the 1800s, when a wave of Eastern European immigrants escaping violence settled in the United States, filling East Coast cities. The Homestead Act of 1862 that gave people the chance to own a tract of land was the impetus for some Jews — who had not been allowed to own land in their home countries — to relocate into the interior of the country.

Largely outnumbered by Gentiles, many Jewish settlers were isolated, and some faced discrimination. When the first generation of Jews born in the Dakotas grew up, their parents urged them to get their education in areas with larger Jewish communities, usually on the coasts. By the 1950s, Jewish populations in cities such as Fargo, Sioux Falls and Rapid City were dwindling. (Although Minnesota's Jewish population has remained steady, the story of how it settled is similar.)

Only two synagogues remained, both of which practice the individualistic Reform strain of Judaism.

"We are not a large enough community to have several congregations," said Stephen Rosenthal, a member of the board of Mount Zion, as well as the board of the Jewish Community Relations Council: Minnesota and the Dakotas. "In this community, we are all Jews."

Although exact numbers are not known, it's estimated that there are fewer than 400 Jews living in South Dakota, a state of 865,000.

"They've maintained a community," said Robin Doroshow, executive director of the Jewish Historical Society of the Upper Midwest. "They are doing what they can under the circumstances with small numbers."

For a community that has survived for a generation without a full-time rabbi, some wonder whether one is necessary at all.

"He brings an additional perspective, but he's not really filling any kind of a void," said Matilda Oppenheimer, a longtime Mount Zion member. "He's just supplementing what we have, and we appreciate that."

Rabbis' roles also are changing with the availability of Jewish information on the internet. Still, there's a need for face-to-face interaction, said Rabbi Alexander Davis of Beth El Synagogue in St. Louis Park.

"Google can't come to your bedside and hold your hand and say a prayer," Davis said. "They're not going to be there when there's a bris or a wedding to celebrate with you, to lift your spirits and lift your chair at a wedding dance."

Since his arrival, many members of South Dakota's Jewish community have been eager to participate in Alperowitz's programs. But there is also some resistance to Chabad's strict reading of Judaism, which doesn't give women an equal role as most mainstream branches of Judaism do. Some Mount Zion members are quick to say that Alperowitz does not speak for them.

The rabbi calls the differences between branches of Judaism "artificial barriers."

"At the end of the day, we're all Jewish people," Alperowitz said.

• • •

On a road trip to visit the Jewish community in Rapid City, the Alperowitzes sang the Hebrew alphabet song and a children's ditty to prepare their daughters for the Jewish New Year. They stopped along the way to let the girls play along the Missouri River, and to buy coffee and vegetables — about the only kosher refreshments they can get on the road.

At the vast pink and gray craters of Badlands National Park, the former city dwellers got out of their car to look at the limitless natural beauty.

"You really see what God made here," Alperowitz said. "In Brooklyn, you barely see the sky."

He wore a long-sleeve shirt and a skullcap; the fringes of his prayer shawl fluttered over his black dress pants.

Among the other tourists, he stood out. It wasn't long before a man spotted him and said, "Shalom." A native South Dakotan now living in New York, the man introduced himself as Rick, and revealed to Alperowitz that he never had a bar mitzvah.

Alperowitz went back to his car and got out the tools of his trade, his spiritual travel kit. On a lookout above the crags of the Badlands, he oversaw Rick's bar mitzvah, decades after his 13th birthday.

Alperowitz covered Rick's head with a skullcap and led him word for word in prayer. He helped wind Rick's arms and head with the leather straps of tefillin.

Then he blew the shofar, those short and long blasts, piercing through South Dakota's expanse, a sound of renewal to signal a new year.