Searchers Looking for Missing Hiker at Grand Canyon National Park

— -- Authorities in Arizona are searching for a 21-year-old San Antonio man who has been missing for almost a week after he was believed to be hiking at Grand Canyon National Park.

Drake Kramer hasn't been seen since he checked out the Bright Angel Lodge Sunday morning, officials said. His family reported him missing on Monday, and search efforts and a missing persons investigation are now under way.

"We don't know what his plans were. He may be hiking, we just don't know," Kirby-Lynn Shedlowski with the Grand Canyon National Park told ABC News today.

While officials do not know why Kramer came to the Grand Canyon, he has been there several times, Shedlowski said. Kramer is an experienced outdoorsman who likes nature, Shedlowski added.

According to his Facebook page, Kramer works at Lowe's and studies geology at a college in San Antonio.

Kramer is described as having brown hair and blue eyes. He is described as 5 feet 7 inches tall and 140 pounds, officials say. Anyone with information can call the National Park Service Silent Witness Line at 928-638-7840.