Southfork, a ranch north of Dallas, was known to millions of viewers as the Ewing family home. Exterior shots of the house and pool were shown when the series aired from 1978 to 1991, although the show wasn't filmed there.
The ranch has been open for tours since the mid-1980s, and now sees more than 100,000 visitors each year. Each room of the house has a theme for each character.
On Saturday, J.R. Ewing's room had flowers and a card for tourists to sign.
"Today is about Larry Hagman and his family," said Janna Timm, a Southfork Ranch & Hotel spokeswoman. "He was such a wonderful person, and we will really miss him."
"Dallas" was recently revived on TNT this summer, and all of the scenes were filmed at Southfork or other places in the Dallas area. Hagman had revised his role as the scheming oilman who would even double-cross his own son.
Linda Sproule of Peterborough, Ontario, had been traveling through the U.S. the past couple of weeks and heard about Hagman's death Friday while in Dallas. She said she didn't know where Southfork was but wanted to come because she was a fan of the show in the 1980s.
"I remember on Friday nights we watched it, and J.R. was bigger than life in some ways," she said after taking the Southfork tour Saturday morning. "This ranch is beautiful. Being here is kind of emotional in a way."
Barbara Quinones and her husband were in town for their daughter's soccer tournament and had already planned to visit Southfork when they heard news of Hagman's death.
"We loved him because he was so ruthless," said Quinones, of Albuquerque, N.M. "This is a sad day, but I'm glad we're here."
Some of the show's stars, including Hagman, came to Southfork for the series' 25th anniversary. The Fort Worth-born actor also had visited several times before the show was revived.
"He was definitely a gentleman, a class act," said Jim Gomes, vice president of resorts at Southfork Ranch & Hotel. "He loved the fans as much as they loved him."