Blake Shelton's ailing father has died. Dick Shelton's health had been in decline over the last year, and a press release from the singer's record label reveals that he passed on Tuesday night in his home state of Oklahoma with loved ones surrounding him.

"I appreciate your understanding during this difficult time and thank you for all your prayers. Your support means the world to me. I love you guys," Shelton said. He and his wife Miranda Lambert's Twitter pages have been quiet since Monday afternoon -- a rarity, especially for 'The Voice' mentor.

Four dates on his current tour have been rescheduled to allow the singer time to grieve, beginning with Thursday night's tour stop in Rapid City, S.D. and including this weekend's dates in Bismark, N.D., Billings, Mont. and Bozeman, Mont. The new dates are listed below.

In December, Shelton dedicated his win at the American Country Awards to his father who was hospitalized hours earlier with pneumonia. At last report, he was scheduled to head home from the hospital on Dec. 8. “Thank you all for the prayers for my dad… Hoping he gets to go home Friday," Shelton tweeted at the time.

The Well Lit and Amplified Tour 2012 will continue on Jan. 26 in Columbus, Ga. with Justin Moore and 'The Voice' runner-up Dia Frampton as openers.

Rescheduled Blake Shelton Tour Dates:

3/20 - Bismarck, N.D.
3/21 - Rapid City, S.D.
3/22 - Bozeman, Mont.
3/23 - Billings, Mont.