The facility in Minnetonka, which opened in 1916, became the state’s largest. It was still treating tuberculosis patients as late as 1976, and was eventually demolished in the early 1990s. (The Minnesota Star Tribune)

Mary Krugerud admits she's "a wee bit obsessed" — and her 15 three-ring binders prove it. For 25 years now, Krugerud's meticulous research has made her the authority on a forgotten niche of state history: Minnesota's long gone but once innovative network of tuberculosis sanatoriums.

From Worthington to Wabasha to Walker, 19 massive round-the-clock tuberculosis care buildings opened between 1905 and 1918 — isolating patients and, in turn, lowering the number of cases of what was commonly called the Consumption.

More than 20,000 Minnesotans died from tuberculosis in the last dozen years of the 1800s when the state's 1.75 million people totaled less than one-third of today's population. TB deaths in Minnesota peaked with 2,543 in 1918. By the Depression year of 1934, when families struggled to care for ailing relatives, 1,600 beds were filled in 14 county sanatoriums.

The big breakthrough came with new drugs in the 1940s, curbing the bacterial scourge. But one of those since-razed sanatoriums, Glen Lake in Minnetonka, was still treating tuberculosis patients as late as 1976 — and 150 cases were reported in Minnesota last year.

"For some reason, Minnesota attracted many men in the 1880s and 1890s who were forward thinkers about sanitation and contagious diseases," said Krugerud, 65, a retired grant writer and medical librarian who lives in Hutchinson.

The state put together a well-regulated web of sanatorium districts, correctly guessing that sick people might stick around these hospitals — away from the yet-uncontaminated population — if they were within driving distance of family and friends.

"People don't stay when they are homesick and lonely," Krugerud said. "They were more likely to remain until cured or dead if they had visitors."

Krugerud moved to the Twin Cities from Dawson in western Minnesota in 1984, landing a job in the medical library at the state-run Oak Terrace nursing home on the old Glen Lake Sanatorium campus near Hwys. 494 and 62 in Minnetonka. Most of those buildings were torn down in 1992 to make way for a golf course.

When the state announced it was closing the place in 1991, Krugerud and some co-workers began videotaping oral histories of former patients and staff. Her obsession was launched.

First, she had to bust through the stigma that silenced many people from discussing their days during the tuberculosis era. She salvaged state Human Services records on their way to the dump, landed a $5,000 state grant to broaden her research statewide and built a website (mnsans.com) with histories for all 19 forgotten facilities.

She's currently writing a book about Minnesota's sanatoriums — not to be confused with sanitariums, which were aimed at addressing mental and physical health in spalike settings. By 1900, anti-tuberculosis groups in North America wanted to distinguish the health resorts from the new tuberculosis hospitals.

One factor driving Krugerud's research is what she considers a skewed history of the sanatoriums. What's been written, she says, often focuses on boredom and abuse. She acknowledges there were dark chapters, but her interviews with Glen Lake patients were loaded with praise for their care. She wants to paint a more complete picture.

The story began in 1904 when the Legislature bought 616 acres near Leech Lake in Walker to construct a Minnesota State Sanatorium for Consumptives. By 1922, it was officially renamed Ah-gwah-ching, an Ojibwe phrase meaning out-of-doors.

Nestled in a pine forest near an Indian reservation, the state picked Walker because its sparse population would pose less infection risks. One problem: It was 180 miles north of the Twin Cities and that limited patient and staff recruitment and retention.

The Walker sanatorium cared for more than 14,000 patients and then served for decades as a state-run nursing home. Everything besides a weather station gazebo has since been demolished.

In addition to 15 county sanatoriums, private facilities popped up as well, including the open-air cottages of the Pokegama Sanatorium near Pine City.

Henry Longstreet Taylor, a TB treatment crusader, had helped create a consumption ward in St. Paul. Growing weary of government's slow pace, Taylor used his own money to open the private hospital along Lake Pokegama.

His weekly rates of about $40 dropped as the county sanatoriums sprung up. Taylor offered patients electric blankets, stock market quotations, private rooms and bathrooms shared by only a few people.

At Glen Lake in Minnetonka, two cottages with 50 beds began serving Hennepin County sufferers in 1916. By 1933, it would grow into the state's largest sanatorium with an average patient count of 706.

Krugerud has yet to cross paths with anyone who has studied Minnesota sanatoriums so extensively. With multi-drug resistant TB ranked the No. 2 worldwide contagious killer in some global areas, behind only HIV, she thinks her research remains topical amid predictions of looming epidemics.

Preventing disease from sweeping through homeless and prison populations, educating contagious children, and managing immigrant health are all timely issues today, as they were in the 1920s, Krugerud says.

"What possessed people to acquiesce to absolute 24-hour-a-day bed rest, sometimes for years?" she wonders. "Answers are varied and interesting — at least I think so."

Curt Brown's tales about Minnesota's history appear each Sunday. Readers can send him ideas and suggestions at mnhistory@startribune.com. A collection of his columns is available as the e-book "Frozen in History" at startribune.com/ebooks.