In this article, he seems to say he will keep searching and he won't keep searching:
http://hosted.ap.org/dynamic/stories/U/UTAH_MINE_COLLAPSE?SITE=WBNSTV&SECTION=HOME&TEMPLATE=DEFAULT
Utah Mine Boss Vows to Keep Searching
HUNTINGTON, Utah (AP) -- Lashing out at criticism he was abandoning six trapped coal miners, the mine chief promised Wednesday to keep searching through the weekend and punch yet another hole into "this evil mountain."
and
Officials said a sixth exploratory hole 1,700 feet below ground would be drilled beginning Thursday, officials said, and Kuzar said it will be in the area where the miners were last believed to have been working.
"This is the last hole," Murray said. "If we don't find anybody alive, there is nowhere else that anyone in MSHA or our company would know anywhere to drill."
Drilling that last hole, he said, will "bring closure to me that I could never get them out alive," although he acknowledged it may not bring closure to the miners' families.
"It's going to have to be in the hands of people a lot better than I am, and it's going to have to be in the hands of the Lord," he said.