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The Mansion History 


The Dreamers of Seventeenth Street

“Go west young man,” Horace Greeley advised his copy boy Ike Walton and the inspiration set fire to a nation. Our original owners were these young men seeking their fortune in the

gold fields of Colorado and on the high plains of Wyoming, . Each from a very modest

background, each having the determination and drive to reach success.

Each found their own destiny and lived in this home.



Erasmus Nagle

The heart of this home began long before Cheyenne was a fort. Erasmus (Elmo) Nagle was born near St. Clairsville, Ohio and grew up in the 1830's surrounded by family with an interesting dynamic. His father was an Irish Catholic (hence the name Erasmus, Latin for St. Elmo) and his mother a Scottish Highland Presbyterian of the Clan Ewing.  The father’s family were from County Cork, Ireland. It was Elmo’s great grandfather that first came to Pennsylvania and then west of Ohio. It was here that he would meet a daughter of the Clan Ewing, one of the first original 6 Scottish Clans. Elmo would have been immersed with both of these ethics and drive to succeed. All the men surrounding him were Masons and he pledged with his father’s lodge.  It was in his DNA to succeed and dream of castles, dragons, and the wee people.

For a farm boy from Ohio, he came far and a typical highlander, he struck out for the west as soon as he had earned enough from tanning hides. Self-made men are like this, They follow the sun and Elmo was not different. He had an eye for business and opportunity, for that was his key.  He struck out for the fields of Colorado and the strike. Quickly realizing mining wasn’t paying off, he began dealing lumber in Colorado City area and Leadville. Enterprising and tireless, he amassed enough for his next adventure, the Wyoming Territory and in 1867 Union Pacific had just established a large depot for the troops.

With investment in hand, Elmo rode into Cheyenne to be greeted with a newly growing town, fort, military, commerce. On the second day, he decided this was where his fortune lies and within the month had secured what would be the beginning of a merchandising empire of the west. As business grew, he would diversify building the telegraph line from Ft. Laramie to Fort Robinson and where he first met General Randall.

Over the next years he would partner with Francis Warren, George Hearst (Randolph’s father) in Deadwood mining, had two large cattle ranches, partnered in the Cheyenne Railroad and Deadwood Stage Line, established the telegraph from Ft. Laramie to Deadwood and Ft. Robinson, He married Emma Houseman in 1872. He was a member of the Masonic and Eagle lodges in Cheyenne.

As a citizen of Cheyenne, Mr. Nagle held a number of civic offices, including commissioner of the Capitol Building Committee. He would assist in selecting architect David Gibbs, a friend from many years ago in Ohio for the capitol. It was then he decided to build the castle but modestly called it a mansion, and Gibbs designed it. John Adam Feick, the 24 year old son of George Feick the contractor, would move to Cheyenne and oversee both buildings. The stones used on the exterior of the mansion had been rejected by the contractor for the State Capitol Building because they had been cut too short, Nagle bought and used them.. The completed residence cost $50,000. This figure included all details, equipment and furnishings.


Mr. Nagle purchased the front part of the property on Nov. 17, 1886 from the Union Pacific for $1. and Emma bought the rear portion from Clarence Converse the same day for $5,000.  Construction began in 1887 and was complete in July of 1888. Unfortunately, Mr. Nagle was only alive to enjoy his mansion for six months. He died of peritonitis leaving a wife, Emma and a son, George. Emma would continue to live in the mansion until she built her last home in 1907 and moved to the 22nd Street home.  Emma then rented the home to their friend General George Randall, from 1906 – 1910.

george morton randall.jpg

Brigadier General George Morton “Jake” Randall was a career military leader that served throughout the west after the Civil War, charged up San Juan Hill with Teddy Roosevelt and John J. Pershing He commanded the American forces in the Philippines again with Pershing, under the direction of Secretary of War William Howard “Bill” Taft until his retirement in 1907. The history of this man is amazing and too extensive for this brief history.

Jake was another Ohio boy who had enlisted in the Civil War and been raised by a military father, General Brewster Randall and mother Harriet. His wife was the daughter of the Commandant of West Point, General Black. The three years they spent in the home saw a parade of generals, Buffalo Bill Cody. President William Howard Taft, Pawnee Bill, and more. He was highly celebrated and admired by his men and friends. On three occasions he served in the same battles as John J. Pershing and with the Warrens, Pershing's in-laws next door, made this the right fit.


As Nagle, he was a member of the Masonic and Eagle lodges in the Cheyenne lodges. After Mrs. Randall passed, the general moved to 18th Street.

Tom Cosgriff

After General Randall moved in 1910, Emma sold the home to her son's close friend Thomas "Tom" Cosgriff 0n April 1, 1910 for $1., another one of these kids who came west from Vermont with his two brothers. They first ran the flocks for Col. Wentworth, then breaking out on their own, created the largest sheep industry in the U.S.  As this grew they bought and created banks, a number of them including the National Bank in Cheyenne. This would be instrumental in financing the building of the town. Thomas and Francis Warren created the Cheyenne Trolley, four banks including Salt Lake City, numerous downtown buildings including two theaters, and ranches to name a few.

Thomas married Rose in 1913, during which they lived between Denver (first owners of the Sullivan Mansion) and Cheyenne depending on business. Many visitors would enjoy their hospitality including Teddy Roosevelt in 1910. Tom was the wealthiest man in Wyoming.


In early 1915 T.A. Cosgriff passed away in Denver with Typhoid, leaving Rose and two small children. Tom died before his youngest was born. Rose and the children would continue to live in Cheyenne off and on but she decided to sell the house to their dear friends and partner, the Warrens. It would be Rose Cosgriff that was responsible for Cheyenne having a Carnegie Library. She was an amazing, accomplished, and considered the most beautiful girl in Cheyenne.

Senator Francis Warren

On March 10 1915,the home was sold to Senator Francis E. Warren and his second wife, the former Clara La Baron Morgan. U.S. senator Francis Emory Warren used his seniority and committee assignments to encourage economic development in the West and to build an effective Republican political machine in Wyoming. Born on June 20, 1844, in Hinsdale, Massachusetts, his generational uncle had first come on the Mayflower. The family originally being French, descended from Geoffrey Duke of Anjou and related to all three King Richards. Warren attended local schools and won the Congressional Medal of Honor for his service with a Union Army regiment during the Civil War. Moving westward, he arrived in Cheyenne in 1868, where he clerked in a furniture store. Soon, he purchased and expanded the enterprise (renaming it the Warren Mercantile Company) and established the Warren Land and Livestock Company and a far-flung set of investments in banks, railroads, and public utilities. Possibly the wealthiest individual in Wyoming, Warren maintained close ties to the powerful Wyoming Stock Growers Association and served as president of the National Wool Growers Association. In 1890 Warren was elected the state's first governor, but he resigned days later after being chosen U.S. senator. He would serve more than thirty-seven years in the Senate, a record unsurpassed until 1964. Warren's seniority, his energy, his unusual knack for political organization and patronage, and his close attention to the state's business interests brought him extensive influence both in Washington and in Wyoming.

Senator Warren’s died in 1929 and Mrs. Warren would continue to live in the home until 1932. On November 15, 1933 upon her remarriage, Clara donated the mansion to the YWCA, fully furnished for $5,000, for use as chaperoned housing for single women and a social place for the people of Cheyenne. It was during the “Y” period that the building contractor’s words proved true and the soft stone exterior began to crumble. In order to preserve the building it was covered in stucco around 1972. This organization would have this home until 1985.


Cheyenne attorney Don and Barbara Sullivan purchased the house on November 8, 1985. For the next 12 years they would raise their family and still visit often. In 1996 they built their current home and in 1997 sold the house. Don has spent his entire career defending those who need it most. He is a champion attorney.  

Jim Osterfoss

Jim Osterfoss purchased the property on August 13, 1997. In that year the “Nagle Warren Mansion Bed and Breakfast” was created. A lifetime career hotel and hospitality industry professional, this was his retirement. From 1997 to 2019, Jim’s vision, love, blood, sweat, and tears went into creating what is now a truly wonderful bed and breakfast. He preserved the home, traditions, and love for the community that the families who lived here were known for. 


As a career hotelier, Jim set a standard of excellence and guest services that was the hallmark of Cheyenne society and the center of hospitality. Over the years the teas became famous, as did his dinner parties and holiday celebrations. It was truly Jim's dream home and life.

The people of Cheyenne say "He never met a stranger"  in true Wyoming tradition.

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