If you ever catch Timothy J. Johnson in a deerstalker hat, it's more likely to be blaze orange than the subdued houndstooth associated with Sherlock Holmes. The game Mr. Johnson stalks really is deer, not London's criminal element. As the recently appointed E.W. McDiarmid curator of the Sherlock Holmes Collections at the University of Minnesota Libraries, though, the native Minnesotan has developed a close bond with the fictional London detective and his world.

Mr. Johnson has charge of what he describes as the world's largest collection of material related to Holmes and his creator, Sir Arthur Conan Doyle. The archive includes the 1887 Beeton's Christmas Annual, which contained the first Holmes story to appear in print ("A Study in Scarlet"); 31 copies still exist worldwide, and Minnesota holds four of them. The collection also features many letters from Doyle to various correspondents as well as original artwork and sketches done by Frederic Dorr Steele, who illustrated Holmes stories for Collier's Weekly. And it contains the correspondence of John Bennett Shaw, a collector of Sherlockiana with close ties to the organization of Holmes enthusiasts known as the Baker Street Irregulars.

Before being named the Holmes Collections' curator, Mr. Johnson, 53, was already the Twin Cities campus library's curator of special collections and rare books, and he continues to oversee those areas. "When you have Holmes and Watson waiting for you and you have all the other stuff besides," he says, "it's not too hard to get up in the morning."

The Holmes Collections officially date back to 1974, when the university bought a private collector's set of first editions. Mr. Johnson credits E.W. McDiarmid, who had been university librarian, with inspiring the purchase. McDiarmid had been part of a group of Holmes-loving faculty members who began meeting in the late 1940s, calling themselves the Norwegian Explorers of Minnesota.

In 1978 the Minnesota's Holmes holdings got a big boost when the university received a large collection of rare Holmes and Doyle material from the estate of a doctor at the Mayo Clinic. "That got everybody in the Sherlockian world's attention," Mr. Johnson says. "It included a lot of very rare first editions, some original artwork, some manuscript material. That kind of put us on the map in terms of Sherlock Holmes collections." Subsequent gifts and purchases have continued to expand the collections.

Mr. Johnson describes himself as being "gradually and enjoyably pulled into the world of Sherlock Holmes." He read the Doyle stories as a kid and grew up watching matinee broadcasts of the movies that starred Basil Rathbone as the hawk-nosed sleuth. In the 1980s, when PBS broadcast its Holmes adaptations starring Jeremy Brett, Mr. Johnson recorded them with his VCR so he could watch them again and again.

An undergraduate history major, he got his graduate degree at the University of Minnesota's library school. He worked as a reference and instructional-services librarian at Barat College, in Illinois, and moonlighted as a medical librarian at a local hospital.

"That almost changed my career because I really liked medical librarianship, and it also happened to be the hospital the Chicago Bears used," Mr. Johnson says. "I bumped into a lot of Chicago Bears there." He wanted to get back to his native state, however, and jumped at the chance to return when the special-collections and rare-books job at Minnesota opened up in 1998.

A good part of Mr. Johnson's work at Minnesota has involved cultivating potential donors as well as tending the rare materials in his charge. He spent 10 years helping to raise money to establish the curatorship named after McDiarmid. A large bequest from another longtime member of the Norwegian Explorers put the fund-raising campaign over the top and allowed the university to endow the position that Mr. Johnson now holds.

Scholarly interest in Holmes comes in waves and is once again on the rise, Mr. Johnson says. He is working to set up a visiting scholars' program, and he'd like to see the collections continue to expand. The library has been keeping an eye on the work of writers who create parodies or pastiches of, or homages to, Doyle's creation. The Minnesota writer Larry Millet, for example, has written a series of Holmes adventures that bring the great detective to the Midwest in the 1890s.

The library has begun the long process of putting the Holmes Collections online. Mr. Johnson would love to add more original Doyle papers and publications, but "it's going to be harder to find that material," he says. "There are a few of the Holmes stories that are floating around in manuscript form that might be available, but you're talking at least six figures to purchase those."

If there's a Sherlockian holy grail, it's manuscript pages from The Hound of the Baskervilles. "That's the one manuscript that Doyle treated a little differently," Mr. Johnson says. The author gave that manuscript to his American publisher, "who basically took it apart and used the individual pages as advertising. They were put on card stock and put in store windows announcing Doyle's new story."

The New York Public Library owns one complete chapter of the manuscript, while Minnesota's collection has four pages, Mr. Johnson says. "If I could get my hands on a few more pages, that would be delightful."