“Strong oil prices didn’t hurt, but it’s not the only thing driving prices,” said Mr. Burgher, who said he had not seen a significant decline in land prices.

“Clearly, the fact that oil prices are going down isn’t going to help ranch prices,” said Brian Sharpe, a U.S. Trust market investment executive in Houston. Whether land prices will fall along with crude, however, remains to be seen. Not only is the economy more diversified, he said, but there are areas within oil and gas, namely refiners, that have not been hit as hard. “I’m not sensing any panic or abnormal stress,” he added.

Statistics from Texas A&M support this observation. Prices per acre increased in each of the first three quarters in 2015, and preliminary numbers for the fourth quarter show the median price per acre hitting new highs. “I don’t think there’s any way we will be unscathed, but there are things that make it different than in the past,” Mr. Gilliland said. He said the large quarterly increase corresponded with a drop in typical acreage, which may suggest that it is the smaller ranches that are selling.

“We’ve had a lot of inquiries because of the price of oil going down,” Ms. Harper said. “People are wondering if it’s a good time to buy.”

It is the trophy ranches that, according to Mr. Ellis, are most dependent on crude. “Of course, it’s not going to look like the 1980s, but we think we can get premium ranches at 2008 prices,” Mr. Ellis said. “We don’t need 20 examples. We just need four or five of these big pieces.” Investors in the fund, he noted, will pay fees only on invested capital; if the fund cannot find suitable ranch land to buy, it will return investors’ money.

It is too early to declare victory on the first ranch fund. Four of the five ranches it bought and restored are now on the market. “We are very confident returns are going to be in the high teens net of fees on our returns,” said Mr. Ellis, who, before starting Sporting Ranch Capital, ran Morgan Stanley’s institutional sales office in Dallas.