A Montana woman was charged on Monday with killing her husband of eight days by pushing him off a cliff at Glacier National Park during an argument and after expressing doubts about the marriage, court records show.

Jordan Graham, 22, was charged with second-degree murder in U.S. District Court in Missoula stemming from the July 7 death of her husband, Cody Johnson, 25, of Kalispell.

Johnson was reported missing to Kalispell police on July 8. Graham told officers her husband had texted her the evening of July 7 to say he was going for a drive with friends and that she believed he was in a dark-colored car that pulled out of the couple's driveway that night, according to legal documents.

Graham on July 11 reported to emergency dispatchers at Glacier National Park that she had found her husband's body below a steep hiking path. It was not immediately clear how far he had fallen.

Graham later admitted to authorities that she had lied about Johnson's death and that she had shoved him off a cliff during an argument while hiking, according to a sworn statement by FBI Special Agent Steven Liss.

Graham said Johnson grabbed her arm during the dispute.

"Graham stated she could have just walked away, but due to anger, she pushed Johnson with both hands in the back and as a result, he fell face first off the cliff," Liss said in the affidavit.

Graham and Johnson were married on June 29. Soon after the wedding, Graham told a friend that she was having second thoughts about marrying him, Liss said.

The evening of July 7, she texted the friend: "Oh well, I'm about to talk to him," and said in a later text: "But dead serious if u don't hear from me at all again tonight, something happened."

When Graham reported finding her husband's body, a park ranger said that was unusual. "It was a place he wanted to see before he died," Graham told the ranger, according to the affidavit.

Graham's federal public defender, Andy Nelson, could not be reached for comment after business hours on Monday.