In 1849 Duerler emigrated from St. Gallen, Switzerland, with his wife, Elizabeth, and at least one child, Gustav (born in 1841). They arrived in Galveston, Texas,but quickly settled in San Antonio. When the city’s San Pedro Springs Park was officially dedicated in 1852, Duerler was already residing on a portion of the recently surveyed parkland. He soon thereafter leased “all that portion of the public square of the San Pedro Creek, now covered by buildings or enclosures occupied by me, and said buildings being about 70 or 80 varas [195 to 222 feet] east of the San Pedro Springs.” Some accounts say that he initially managed a portion of the park as a concessionaire, offering rides in a rowboat and inviting the local Beethoven Männerchor to give Sunday performances. What is more certain is that in March 1864 Duerler officially entered a twenty-year lease with the City of San Antonio to operate concessions in the park exclusively. In accord with the lease, he maintained and developed the park, adding several natural features and attractions over the next ten years. Duerler constructed five shallow, spring-fed ponds, spreading out in the shape of a fan, just to the west of the naturally occurring lake on the site. He embellished the ponds with tropical plant materials and stocked them with fish. He also established a museum and began collecting exotic animals, the latter eventually becoming the core of the San Antonio Zoo, which would later be housed in Brackenridge Park. Among the other attractions added by Duerler were a racecourse, a tropical garden, and a beer hall. Dueler died in 1874 after being injured in a fall. The management of the park then passed to his son Gustav until 1877. The elder Duerler was initially buried in San Pedro Springs Park, but after his grave was desecrated, he was reinterred, in 1886, in City Cemetery No. 1.