He was appointed Sacramento County Surveyor in 1914 and was reelected to that office several times. Butler believed that road and bridge work should be under the direction of competent engineers and should be built to the highest standards and of the best materials. He also believed that roads and bridges should be maintained to a high standard ensuring long life.
During the period when Butler first became the County Surveyor, the counties were responsible for providing the bridges for State Highways. The 12th Street Bridge over the American River served the State Highway coming down Del Paso Boulevard. Butler initiated changes during construction of the bridge to improve the scour resistance of the footings, and on another occasion successfully faced down the contractor who was delivering substandard materials into the concrete forms.
Butler planned and designed a commercial gateway road project in Folsom to connect the fruit producing areas across the river in Orangevale, Fair Oaks and Carmichael, with the railhead in Folsom. This project required three new bridges and utilized Theodore Judahís abandoned Central California Railroad bed. One bridge was build during each of the three years that it took to build this economically important project. The Orangevale Avenue Bridge over Gold Creek was the first, completed in 1915. This bridge was the first open spandrel reinforced concrete arch, a relatively new structure type, built in Sacramento County. The bridge over the American River was completed in the final year, 1917. Butler advocated County furnished cement for this project in order to assure quality. This road project was considered one of the finest in California.
Butler was ahead of his time as a proponent for a property tax to pay for public works rather than using bond issues. He pointed out that after paying the service interest on bonds that public works projects end up costing twice as much.
There are 38 bridges built by the County during Butlerís time in office that are still in use today. He had oversight of the four Joseph Strauss bascule bridges built over the Sacramento River; he built the 12th Street Bridge and the Folsom Rainbow Bridge over the American River. The H Street steel through Truss Bridge over the American River was designed and built under his leadership. Drury Butlerís engineering career spanned a time through the 1920ís when public infrastructure was in its heyday with the building of flood control projects, major bridges, dams, sewer systems and buildings, many of which he was involved with.
Drury Butler joined the American Society of Civil Engineers (ASCE) in 1919 and was a founding member of the Sacramento Section in 1922.
Butler was on advisory committees working with the California Highway Commission, the California Department of Motor Vehicles, the Association of California County Supervisors, and the Trucking and Automobile Associations to advocate legislation regulating engineering standards and the California Vehicle Code. Butler strongly advocated professional licensing for Civil Engineers. Finally with the collapse fo the St. Francis Dam in 1928, his proposed licensing legislation was passed. He held California Civil Engineering License No. 46.
In 1935, after 20 years of service as County Surveyor, Butler returned to private practice and designed two subdivisions in the City of Sacramento. He also served as a consultant designer and engineer to the Cities of North Sacramento, Galt, and Escalon. In that capacity he designed water systems, sewage treatment plants or subdivisions as needed. He also surveyed mining claims, which was an art in itself.