Parker is situated within a mesa that overlooks the Colorado River with the elevation of some 450 feet over the sea level and in the northernmost corner of the Indian Tribe reservation on the Colorado River. The community of Parker is also located in the Sonora Desert that is located close to the low rugged mountains and the river bottomland. The Riverside and Whipple Mountains are located to the southwest and north respectively and the Gibraltar Mountains are located close to the community to the east. The Indian Tribe reservation is located on both sides of the Colorado River at a point 50 miles south from a point five miles north of Parker, and contains over 264,000 acres. The reservation was established by an act of Congress and approved by the President in 1835 for all Native Indians that lived next to the river. The Tribes represented on the Reservation include the Hopi, the Navajos, the Chemehuevis, and the Mohave.

In 1909, town site of Parker was laid out and surveyed by a railroad location engineer. In 1871, a post office was established January 6, 1871, on the Colorado River Indian reservation in order to serve the Indian agency. The namesake of the post office and the settlement was General Eli Parker who was the Commissioner of Indian Affairs when the Colorado River Indian reservation was established by Congress in 1865.

In 1905, a railroad was established in its current location, and the Parker post office was relocated upstream four miles to the railroad. It was only logical that the railroad would run through the center of the community because the town site of Parker was laid out for the purpose of providing a shipping and watering station, and a railroad stopover. The settlement was laid out on a grid of 100 foot streets that formed a 300 x 4000 foot blocks with twelve 50-foot-wide lots to a block. In 1910, the Federal Government auctioned off lots.

In 1867, the development of agricultural products, which is the current mainstay of the economy in the region after Congress appropriated $50,000 for the Indians’ irrigation system. This funding was used for the building of the Grant-Dent canal between 1867 and 1871. Early irrigated farming was painstaking and dismal as river flooding washed out new equipment and constructing, wells were serving alkali water, canals caved in, and banks washed away. However, these early failures didn’t discourage those who had dreams of a great empire in agriculture. There were only 600 acres of land owned by Indians that were being irrigated by 1914, and inadequate drainage was water logging most of those acres. The population of Parker was only 90 people by this time, and the primary economic activity of the settlement was a shipping and service center for the mining and agriculture activities that were scattered throughout the region.

While the mining activity decreased, the agricultural activity on the reservation continued to grow, in spite of the problems and frustrations connected with irrigation. More than 5,000 acres of river bottomland were under irrigation by 1936. There were some 10,500 acres of land being cultivated, and the water level that was guaranteed provided by the dam accelerated the expansion of agriculture by 1941, when the Headgate Rock Dam was built. Some 38,000 acres of land had been cleared for farming by 1955. The community of Parker became a small agricultural shipping and service center. The expansion of agricultural continued at a rather fast pace while the Headgate Rock Dam ensured a controllable water level of the river. However, farming was plagued by excessive salts, improper draining, and high water tables, which rendered numerous acres useless for farming. During the next seven yours, this problem was resolved, and the land being cultivated accounted for 34,000 acres by 1963. Cotton gins we built in the community of Parker as Cotton became the big crop. Parker existed as a small community providing services and supplies to the mining and agricultural operations of the region from 1914 through 1937, it provided community facilities to the administrative and construction who worked on federal projects next to the Colorado River during the late 1930’s. Winter residents, sportsmen, and tourists also became attracted to the smooth waters behind the Headgate Rock Dam following WW II.

A highway bridge was completed across the Colorado River that connected California with Arizona in 1937. This ended the ferry service that had been in operation for 27 years by Joe Bush and his wife, Nellie. The Parker Dam was completed in 1928, which ensured better water control of the river and created a lake about 16 miles long and 700 feet wide known as Lake Moovalya, and Indian word meaning “blue water”. Thus the creation of, and ease of access to Lake Moovalya. To some extent, the community of Parker transformed into a community that provided services and supplies to boating hunting, and fishing enthusiasts from a service center for mining and agricultural mining workers. However, the agricultural expansion of the lands of the Indian Reservation had come to a standstill as the result of the inability to provide long-term leases. Congress granted the right to make 99-year non-agricultural leases of Indian Reservation lands in 1962 and provided the right to make 25-year agricultural development leases in early 1963. Also in 1963, the US Supreme Court decreed that the Colorado River Indian Reservation was entitled to sufficient water to irrigate 107,588 acres of agricultural lands.

The year 1948 brought the official incorporation of Parker as a town. Parker also annexed some 13,000 acres of noncontiguous land 10 miles to the southeast known as Parker South in 1980. Voters established La Paz County by initiative petition from the northernmost part of Yuma County in 1982. Parker was La Paz County’s county seat by 1983.