Founded in 1922, the Houston Zoo is an exciting live animal adventure that provides a unique educational and conservation resource serving 1.5 million guests annually.  Set in a 55-acre lush tropical landscape, the Zoo is home to more than 4.500 exotic animals representing more than 800 species.  Operated by the not-for-profit Houston Zoo, Inc., the Houston Zoo is dedicated to the conservation of wildlife, providing engaging educational experiences for our guests and creating naturalistic animal habitats.

In 1920, the U. S. government thinned the bison herds in the national parks and bestowed one of the excess animals on the City of Houston. The lone bison, who came to be known as Earl, was housed in Sam Houston Park. The fenced home was referred to as the zoo, and a deer was donated to keep Earl company, thus instantly doubling the size of the zoo's population.

In 1922, the zoo was moved to Hermann Park. To this suburban wilderness came the Houston Zoo - a fence enclosing a small tract of land with wooden cages for birds, monkeys, and small animals. Most of the inhabitants were acquired from local folks who had tired of their exotic pets. A few were secondhand circus animals.

By 1923, it had become obvious that the zoo needed a keeper. Hans Nagle was chosen and proved equal to the task. By 1924, citizens and institutions had begun to join the city in buying animals for the zoo.

The zoo encompassed 30 acres by 1925, and the city had spent $10,000 acquiring animals. In 1926, an aviary and monkey facility were built. Today, the Houston Zoological Gardens covers 55 magnificently landscaped acres and is home to over 5,800 animals. Through an admission fee instituted in January 1989 and property taxes, the city pays zoo personnel salaries and animal feed bills and maintains the grounds and buildings. Support for the zoo also comes from other organizations. The Zoological Society raises funds by operating the zoo's food and gift concessions, and by soliciting monies for special projects. Zoo Friends sponsors the biannual Zoo Ball and off-year special events to purchase new animals and build new displays. The Docent Organization provides support through the purchase of supplies, biofacts and providing invalualble volunteer support for zoo interpretation and special events.