The deal "demonstrates the power of working together to address the needs of an imperiled species," said Noreen Walsh, Mountain-Prairie regional director for the service, in a statement.
The deal expands two existing conservation areas in the dunes that are separated by a couple of miles. One area will be expanded from 207 acres to 266. The agreement also provides several islands of habitat amounting to an extra 263 acres between the two conservation areas.
"This expansion protects 88 percent of the species' occupied habitat in this area from off-road vehicle use," the Fish and Wildlife Service said in a statement.
The conservation agreement was signed by the Fish and Wildlife Service, the U.S. Bureau of Land Management, the Utah Department of Natural Resources and Kane County.
"The Utah Department of Parks and Recreation is extremely happy about this decision," said its director, Fred Hayes, in the statement. "We believe this is in the best interest of the CPSD tiger beetle and the recreating public who enjoy Coral Pink Sand Dunes State Park."
Juan Palma, Utah state director for the BLM, added, "We are committed to managing public lands to conserve the tiger beetle while supporting the recreation and outdoor activities that boost local economies in southern Utah."
When details of the proposal to expand conservation were first announced earlier this year, Kane County Commissioner Jim Matson said it was needed to help keep the state park open. "It's a factor in our local economy and we want to make sure we are doing the right thing for the habitat."
The Fish and Wildlife Service proposed almost exactly a year ago to list the beetle as threatened because of perils from off-road vehicles, drought and climate change.
In recent years, the beetles' population count has hovered between 1,100 and 1,500, according to entomologist Barry Knisley, who conducts a population survey at the dunes every May.
This species is just one of more than 100 tiger beetles species in North America and it is found nowhere else, probably because it is uniquely adapted to the Coral Pink Sand Dunes' distinct environment, said Knisley, an emeritus biology professor at Virginia's Randolph-Macon College.