In the late 1800s , the first American settlers arrived in the area .
In the late 1800s , the first American settlers established small towns along the creek 's confluence with the Santa Ana River , including Rincon ( later changed to Prado ) .
In the late 1800s , the first American settlers arrived in the area and established small towns along the creek 's confluence with the Santa Ana River , including Rincon ( later changed to Prado ) .