Henry Franklin Hoyt, pioneer doctor, son of Lorenzo and Sarah (Terrell) Hoyt, was born on January 30, 1854, in St. Paul, Minnesota. He grew up during the Civil War and the Santee Sioux uprising, became fascinated with the West, and at eighteen obtained his first job with a surveying crew for the St. Paul and Pacific Railroad. After attending the University of Minnesota in 1870–71, Hoyt began medical training with his uncle John Henry Murphy, a doctor, and also as an intern at Church (later St. Luke's) Hospital in St. Paul. In 1875–76 he attended Rush Medical School in Chicago. "Itchy feet" prompted Hoyt to interrupt his medical studies and seek a new location out west. In the spring of 1877 he reached Deadwood, South Dakota, with the hope of finding a gold mine and establishing his medical practice there. His prospecting efforts were unsuccessful, however, and in September he made his way to Santa Fe, New Mexico, and thence south to the Pecos River valley. Near Roswell, New Mexico, he put up at the ranch of John S. Chisum, who told him that Tascosa, in the Texas Panhandle, was in need of a doctor.
In November 1877 Hoyt arrived at Tascosa in the middle of a smallpox outbreak and became an immediate hero after saving the life of Casimero Romero's adopted daughter, Piedad, by applying a poultice of gunpowder and water. Since Tascosa's populace was unable to support a full-time physician, Hoyt worked as a mail carrier between Tascosa and Fort Bascom and also as a cowboy. While riding the LX Ranch he met Charles Siringo and James H. East, with whom he maintained lifelong friendships. Hoyt also met Billy the Kid (Henry McCarty) in a Tascosa saloon; he once reportedly gave the outlaw a lady's watch, won in a poker game, for the Kid to present as a gift to his sweetheart, Paulita Maxwell. In October 1878, just before Hoyt departed for Las Vegas, New Mexico, Billy presented him with a sorrel racehorse formerly owned by Sheriff William Brady, whom the Kid had killed during the Lincoln County War. To prevent any embarrassment over the horse's ownership, Billy wrote Hoyt a bill of sale, witnessed by the owners of a local general store.
Hoyt resided for a time at Las Vegas, where for extra money he tended bar at the Exchange Hotel, then moved his practice to Bernalillo. There he remained until 1881, when he went back east to continue his studies. In March 1882 he received his M.D. degree from the Columbus (Ohio) Medical College. He then returned to St. Paul, where he became a surgeon for several railroad companies. On May 23, 1888, he married a widow, Ella Owens Gray, who had a son by her first marriage; the couple later also had a son of their own. In 1889 Hoyt was appointed head of the St. Paul health department.
At the outbreak of the Spanish-American War in May 1898, Hoyt enlisted in the medical department of the United States Volunteers as chief surgeon, with the rank of major. He served under Gen. Arthur MacArthur (father of Douglas MacArthur) in both that conflict and the subsequent Philippine Insurrection, where he was wounded in action. He received the Silver Star for gallantry in action during the insurrection and rose to the rank of surgeon general. After his discharge in October 1902, he practiced medicine in El Paso. In 1910 he moved to Long Beach, California, where he remained until his retirement. In his autobiography, A Frontier Doctor (1929), appears one of the last eyewitness accounts of the Panhandle frontier. Soon after its publication, he joined his sister Sue and her husband, Judge George R. Harvey, for a three-month vacation in the Pacific, which included a visit to his old haunts in the Philippines. On the return voyage, while his ship was docked in Yokohama, Japan, Hoyt died suddenly, on January 21, 1930. Funeral services were held in Long Beach on February 11.