In the 1950's, south of White City, there were few homes. The area was a peaceful little slice of Florida. Not much more than a fish camp (Pruitt’s) along the St. Lucie River, roaming cattle from the few area ranches, and a fruit stand or two along the two-lanes of U.S. 1.

Then Gardner Cowles, (shown front right, with Mackle brothers) owner and publisher of Look magazine, discovered the St. Lucie River. He was one of the first to realize the potential of postwar Florida development. He purchased 8,500 acres south of Fort Pierce. In January of 1953 Cowles' St. Lucie River Land Company filed the plat for Unit 1 of River Park, the south St. Lucie County sub-division that was nestled just outside the northern border of soon to be Port St. Lucie.

Mr. Cowles developed a nationwide advertising campaign, designed primarily to attract retirees. He used magazine and newspaper ads to promote the areas natural beauty. He attracted buyers by marketing tropical living and a fishermen's paradise. When prospective buyers came to look at the property they were given a serene boat ride down the winding river. They almost always signed a contract when the tour ended.

Entrada Avenue and East Arbor Avenue were the first two streets laid out in his plan within River Park. Four homes built for the Youngerman Estate Company of Miami were completed in 1956. Guy & Gladys Clark were the first residents to move into the new development in 1957. Their new home was at 216 East Arbor. Four other families quickly followed, and by September of 1958 River Park had 42 families. There were no shopping centers. The closest store was 12 miles north in Fort Pierce. At first mail was delivered at Fort Pierce, then a FFA mailbox was put out facing U.S. 1 for the new residents. That same month General Development Corporation purchased the River Park sub-division from Cowles. Thus began the great Port St. Lucie land rush !

The unique evolution of the River Park sub-division was nothing short of remarkable. It was at first intended as the beginning of this new city to be named Port St. Lucie. However, as time progressed and circumstances prevailed, recognizing the differences between the vision of the developer and that of the River Park residents, the city was chartered to exclude River Park. To this day River Park abuts the northern border of Port St. Lucie in unincorporated St. Lucie County. While its residents, many of whom were and remain a vital part of the history of the City, are not within the boundaries of Port St. Lucie, they are a part of the fabric of the City.