Major-worthy conditions test golfers at U.S. Senior Open

Colin Montgomerie, shown at the 2015 U.S. Senior Open ( USGA )SACRAMENTO, Calif. — This is the U.S. Senior Open, all right. Here at Del Paso Country Club, all the earmarks are present and accounted for: skinny fairways, heavy-duty rough, firm and fast greens.

The rough, both alongside the fairways and around the greens, is suffocating. It swallows golf balls.

"As tough as it's ever been for a U.S. Open or U.S. Senior Open," said Tom Watson, the first-round leader with a 66. "For me, that defines a U.S. championship."

Colin Montgomerie agreed. "My game was built on these type of courses," he said after his second straight 2-under-par 68. "It (the mentality) is four rounds, fairways and greens.…