OYSTER BAY:  The massive elk, moose and buffalo heads are back up. The lion-, tiger- and bearskin rugs are back down and the Lincoln, Jefferson and Grant portraits have been cleaned.

Sagamore Hill, the Long Island mansion that was Theodore Roosevelt's home and "Summer White House," is set to reopen following an extensive four-year, $10 million renovation by the National Park Service, a fitting custodian for the man who championed historic preservation.

Every one of the 12,000 items owned by the 26th president, including an estimated 10,000 books and dozens of "trophies" from his hunting expeditions, were removed from the 28-room, Queen Anne Shingle style mansion and then painstakingly repaired and replaced exactly where he left them.

"We hope that if he walked through the front door right now, he would think he was back during the presidential years," said Susan Sarna, curator at Sagamore Hill for the past 25 years and project manager for the renovation. "We really do feel if he was in the library he would feel like he was brought back in time to his home."

National Park Service officials received funding for the project in 2008, and after three years of planning — and packing — actual construction began in 2011. In addition to other improvements, the roof was replaced, foundation repaired and entire house's electric system rewired.

The three-story home built in 1885 and named by Roosevelt after the Indian chief Sagamore Mohannis has 15 bedrooms and three bathrooms, as well as sitting rooms, offices and a large porch. It sits on 83 acres high atop a hill overlooking an inlet that leads to the Long Island Sound, about 35 miles east of Manhattan.

"This is the only home he actually owned. It was the summer White House; he was the first president to actually work during the summer because of the invention of the telephone," Sarna said.

Yanek Mieczkowski, a history professor at Dowling College on Long Island, said the larger-than-life Roosevelt had a reputation for traveling the globe, but he always returned to the Long Island home where he died in 1919.

"Spending summers there, he camped, hiked, hunted, fished, and rode horse-back with his family — pursuits that he enjoyed and that matched his formidable energy," he said. "Roosevelt made the presidency portable by bringing staff and paperwork to Sagamore Hill, but the retreat also functioned as his release valve."

Sarna contends scholars who study Roosevelt can never completely understand the man without visiting Sagamore Hill. She said filmmaker Ken Burns came to Sagamore Hill and filmed part of his PBS documentary, "The Roosevelts," before renovations began.

"This home is his life. You look at his library and everything in there is what he surrounded himself with," she said. "If you really want to know exactly who this man is you need to come here and sit in his chair, so to speak. He said Sagamore Hill was his favorite place. He liked it more than the White House."

The first floor features his office/library, where he entertained visiting dignitaries and held preliminary talks aimed at ending the Russian-Japanese War. Roosevelt was the first US president to win the Nobel Peace Prize for those efforts.

A bright sitting room, decorated with colorful paintings selected by his wife Edith, sits opposite the library. She insisted no animal heads were permitted there, Sarna said.

A long dark hallway featuring a large head of an African cape buffalo over a fireplace, leads to the North Room, or trophy room. It is adorned with numerous elk and buffalo heads and dozens of mementos from his presidency and life before the White House. Roosevelt's rifle and his Rough Rider hat worn during the Spanish-American War are perched atop the antlers of one of the elk heads, exactly where he kept them when he was alive, Sarna said.

The second floor has the family's living quarters, where the Roosevelts reared six children. Roosevelt's "gun room," an early 20th century version of a "man cave" has two desks and a gun cabinet. A prolific writer and reader, Roosevelt was known to read as many as two books a day and authored about three dozen of his own.

The official reopening is scheduled for July 12. Dignitaries including Interior Secretary Sally Jewell are expected to attend. Daily tours will begin the following day; reservations are currently being accepted.

Sarna, a former teacher, particularly enjoys visits from schoolchildren.

"Maybe they'll be inspired to be a better person or take one of his writings and actually read it. If we can do that then we've actually done something."