Case Details:Alejandro Pilar Vasquez, also known as Alex "Tank" Gay or Vazquez, was 24 years old at the time of his disappearance and had been living intermittently in Dodge City, Kansas, with his father before returning to South Dakota's Pine Ridge Indian Reservation for a visit the weekend before Halloween 2015. He was staying with his brother at a residence roughly five miles west of Kyle, South Dakota. In the early morning hours of October 29, 2015, Vasquez left that residence, near American Horse Creek, and has not been seen or heard from since. He did not have a cellular phone or a debit card with him at the time. He was last known to be wearing a gray or charcoal shirt, plaid shorts with blue stripes, and white sneakers with a black stripe (reported in different sources as Nike or Converse). Vasquez is described as 5 feet 7 inches tall and about 200 pounds, with brown or black hair worn shoulder-length at the time and brown eyes. He is Hispanic and American Indian/Alaska Native and is a member of the Oglala Sioux Tribe.

The case is investigated by the Bureau of Indian Affairs Office of Justice Services Missing and Murdered Unit, with Special Agent Tyler Little Finger as case agent; tribal police on the Pine Ridge Reservation were involved in the initial search response. Ground searches using ATVs and a search aircraft, and a volunteer search organized by family members in January 2016, did not locate Vasquez. His case remains open. The Missing and Murdered Unit is offering a reward of up to $5,000 for information leading to his location. The case is also listed with NamUs (#MP31281). Tips may be submitted by texting BIAMMU to 847411, calling 1-833-560-2065, or emailing OJS_MMU@bia.gov.