The Fremont County Sheriff's Office is still searching for a missing 70-year-old man who disappeared from the Riverton area one week ago and hasn't been heard from since.

Jose "Pepe" Pereda was last seen headed south on South Federal Boulevard at 11:30 a.m. Wednesday, Sept. 5. His only known destination was the Sand Draw Landfill outside of Riverton, but he never arrived.

Pereda was driving a white single-cab 2002 Toyota Tundra. The truck has county 10 license plates and is missing both rear hubcaps. It was last seen with trash in the bed of the truck.

According to a news release from the sheriff's office, Pereda is described as having memory loss. He may be disoriented or confused.

Fixed-wing aircraft have been used over the last several days to search thousands of acres in the Sand Draw and Gas Hills areas, as well as areas further south of Beaver Rim. The sheriff's office says other areas of the county have been examined without results.

"Mr. Pereda has disappeared, there have been no sightings in the last seven days as of Wednesday morning," Undersheriff Ryan Lee said in a statement. "We have searched a very large area of Fremont County with absolutely no results, no evidence, and no further leads to act upon at this time."

A joint investigation into the disappearance is being conducted by the sheriff's office and the Wind River Police Department.

Pereda is described as a Hispanic male standing 5'7" tall and weighing 130 pounds. He was last seen wearing a gray/black flannel long sleeve shirt and black pants.

Anyone with information is urged to immediately contact the sheriff's office at 307-332-5611.

The sheriff's office is also asking any antelope hunters who will be in remote, desolate parts of Fremont County this weekend to be on the lookout for Pereda.