Dayton's bill, SB163, was drafted at the request of the Utah Department of Natural Resources.
Division of Wildlife Resources Director Greg Sheehan argues the department is obligated to manage resources for populations of listed species, even if the population was established illegally.
"We don't want to have backyard biologists deciding what these populations ought to look like and where they reside," he said.
But the wildlife manager could provide no examples of anyone ever establishing a population of endangered animals in Utah.
Sheehan did mention burbot, carp, quagga and feral hogs — none of which are endangered — illegally or inadvertently moved around the state causing ecological and economic problems. Dayton's bill would do nothing to deter placement of such invasive species.
Introducing an endangered species "without lawful authority" would be a third-degree felony under Dayton's legislation, punishable by up to five years in prison. The law would apply not only to listed species, but also candidates for an endangered listing, such as the greater sage grouse and spotted frog.
Relocating fish and wildlife already is a misdemeanor under Utah law, so Dayton's bill simply elevates the criminal sanction if the offense involves an endangered or threatened animal.
Critics wonder if the bill is a solution looking for a problem, since renegade planting of protected wildlife rarely if ever happens and is already prohibited under federal law.
More likely, the law is geared toward preventing imperiled species from expanding their range and legitimate efforts to re-introduce rare animals into their native habitat, according to Taylor Jones of WildEarth Guardians.
"It looks like if passed it could put some restrictive roadblocks to recovery efforts," said Jones, a conservation biologist active in efforts to recover the imperiled Utah prairie dog.
Dayton said she wanted to go much farther, with even tougher penalties.
"I am really disappointed with this bill," she said. "I wanted this bill to include plants."
Committee members sent the bill to the full Senate with a unanimous vote.