Jim Posewitz is confident he will see a huntable herd of free-roaming, wild bison somewhere in Montana in his lifetime. "We'll have to hurry, though," he said, smiling. Posewitz is 76. A Montana conservationist, hunter, author and promoter of hunter ethics, Posewitz has lent his voice to the National Wildlife Federation's push to have bison restored to the 1.1-million-acre Charles M. Russell National Wildlife Refuge in northeastern Montana. "What better place, what better species and what better time?" he said.