Willis Day Twichell, surveyor, was born on March 24, 1864, in Hastings, Minnesota, to Daniel Wilson and Sarah Catharine (Coons) Twichell. His mother died when he was four, and the boy spent part of his early years at his uncles' farms. His father, who had remarried, moved to Madison County, Ohio, in 1876, and Willis attended public schools in Minnesota and Ohio. In 1883 he graduated from National Normal University in Lebanon, Ohio, with a degree in civil engineering. Immediately thereafter he set up his civil engineering practice in Springfield, Ohio. In November 1885 he was employed by a local immigration company to go to West Texas and stake out the proposed county seat of Garden City, Glasscock County. At Big Spring in January 1886 Twichell met William S. Mabry, a surveyor employed by the Capitol Syndicate (see XIT RANCH), which was then building the Capitol at Austin. For Mabry, Twichell surveyed the Yellow Houses Division of the XIT Ranch, which the syndicate had established on lands it received for building the Capitol. After finishing this work, Twichell surveyed the Spring Lake Division. Twichell's education in cadastral surveying, astronomy, physics, and mathematics enabled him to use more precise methods of surveying than those that depended upon following directions indicated by a magnetic compass. With cadastral surveying, his east-west survey lines corrected for the curvature of the earth's surface.
Throughout the late 1880s Twichell and Mabry conducted right-of-way surveys for the Fort Worth and Denver City and Southern Pacific railroads in West Texas. During that time they maintained an office together in Tascosa, until Twichell moved his office to Amarillo in 1890. He continued doing railroad surveys and in 1893 helped plat the city of Enid, Oklahoma. On September 4, 1895, he married Eula Trigg. They had four daughters and a son; another son died in infancy. Twichell became involved in Amarillo's civic affairs and joined in the fight for prohibition; once he played host to Carrie Nation. He also taught school for two years (1895–97) at the precursor of Amarillo College. He also started the school band and in 1901 organized the Amarillo Concert Band. Between November 1900 and March 1916 Twichell worked as a state surveyor, although he kept his Amarillo office until he moved to Austin in 1918. He retired from active business on January 1, 1934, to become a consultant and moved to San Angelo, where he lived until his death on September 23, 1959. He was buried in Lawnhaven Cemetery in San Angelo. Later cadastral surveyors retracing his lines found them to be of high accuracy. His survey records, composed of many field books, working sketches, some 200 finished maps, field notes, and about 50,000 pages of correspondence, were purchased by six major oil companies a short time before Twichell's death and are kept in a private depository in Midland.