After thrashing the depleted Western Force 69-17 last week and then seeing off the gallant Queensland Reds 22-12 in Brisbane on Saturday, the Lions almost effortlessly established a commanding 38-0 halftime lead.
After holding out for some seven and a half minutes, Country leaked their first try when winger Alex Cuthbert squeezed over in the right-hand corner.
Hogg nailed the sideline conversion before halfback Conor Murray crossed two minutes later to open the floodgates.
The tourists added further five-pointers in the 12th, 20th, 26th and 33rd minutes through Hogg, hooker Richard Hibbard and hulking Welsh winger George North, who snared a first-half double.
Scoring at almost a point a minute, the Lions threatened to rack up a cricket score after the break.
But they only managed another four more five-pointers - coming O'Driscoll, O'Brien and replacement winger Leigh Halfpenny, who collected a double.
O'Driscoll admitted he would have preferred to have put Country to the sword in the second half.
But coach Gatland insisted the tourists were where they needed to be ahead of the three-Test series with the Wallabies starting in Brisbane on June 22.
"There's great harmony within the squad," Gatland said.
"The boys who didn't play today worked really hard and we're undefeated.
"So if we could win the next two games (against the NSW Waratahs on Saturday and Brumbies next Tuesday) before Brisbane and arrive in Brisbane undefeated, it would be a good positive frame to arrive in."
Country captain Tim Davidson and centre Lewie Catt, who returns to work on Wednesday as an electrical engineer, said they would savour the experience of playing the Lions for the rest of their lives.
"I was absolutely proud of the guys in the second half," Davidson said.
"I couldn't have asked for any more. It was a super effort."
Lions tour schedule:
Lions 69 Force 17
Lions 22 Reds 12
Lions 64 Combined NSW and Queensland Country 0
Lions v Waratahs, June 18
Lions v Australia 1st test, June 22
Lions v Rebels, June 25
Lions v Australia 2nd test, June 29
Lions v Australia 3rd test, July 6
- AAP