where did yellow crookneck squash come from?

Answer 1

Most of our pumpkins and squash originated in South America and Mexico where remains of wild or cultivated squash have been found dating back to around 9,000 B.C.
http://www.umass.edu/umext/mac/Newsletters/Autumn%201998.htm

Modern day squash developed from the wild squash that originated in an area between Guatemala and Mexico. While squash has been consumed for over 10,000 years, they were first cultivated specifically for their seeds since earlier squashes did not contain much flesh and what they did contain was very bitter and unpalatable. As time progressed, squash cultivation spread throughout the Americas, and varieties with a greater quantity of sweeter-tasting flesh were developed. Christopher Columbus brought squash back to Europe from the New World, and like other native American foods, their cultivation was introduced throughout the world by Portuguese and Spanish explorers. Today, the largest commercial producers of squash include China, Japan, Romania, Turkey, Italy, Egypt, and Argentina.
http://www.whfoods.org/genpage.php?tname=foodspice&dbid=62

Cucurbita moschata: Prior to European contact this species was distributed from northern South America, to southern North America (Evolution of Crop Plants, Smartt and Simmonds, 1995). Earliest remains come from Huaca Prieta in the Peruvian coastal desert from 2000 BCE. Archeological evidence points to cultivation in Tamaulipas, Mexico by 1400 BCE. Winter, or Canada Crookneck squash, Butternut squash, Golden Cushaw, and the Cheese Pumpkin are included in this group.
http://www.colonialwilliamsburg.com/history/CWLand/resrch12.cfm