A federal lawmaker from Arizona wants the Interior Department to investigate an active conservative group for what he alleges is unregistered lobbying.

In a letter to Interior Inspector General Mary Kendall, Rep. Raúl M. Grijalva (D) on Wednesday called for an investigation into the American Legislative Exchange Council’s “aggressive effort” to change state laws regarding public land use. The group’s work constitutes unregistered lobbying, he argues.

“Despite actively pressing state lawmakers on a range of issues, ALEC has failed for decades to register as a lobbying organization in states where it has promoted changes to state laws,” Grijalva writes.

In the letter, Grijalva also requests an investigation into how ALEC’s efforts have affected department employees. ALEC’s position, he argues, is consistent with those of Nevada rancher Cliven Bundy, whose decades-long fight resulted in a weekend showdown between government officials and anti-government militia groups.

“This seems like high political theater on the part of Rep. Grijalva,” said ALEC spokesman Bill Meierling. State lawmakers have a clear interest in managing public land within their borders, he said. And Grijalva, as the ranking member of the House Natural Resources subcommittee on public lands and environmental regulation, clearly has an interest in maintaining federal control of such lands, he added.

“Mr. Grijava’s allegations are frivolous, fail to cite the regulations governing lobbying activity and are no doubt part of a long time effort by those who disagree with ALEC’s ideas to discredit the organization, rather than debating its proposals,” the group said in a written statement.

ALEC, which claims one in four state lawmakers as members, has in recent years become a target of the left for both supporting conservative policies and giving corporate interests what critics allege is an undue influence in the policymaking process.

The group maintains a library of hundreds of model bills on a variety of subjects intended to be copied and modified for state and local lawmaking. It has both corporate and lawmaker members who work side-by-side in policymaking workshops, although the group says lawmakers have the initial and final say over model bill language. ALEC’s Web site lists eight model policies related to public lands, including a resolution states can pass urging Congress to hand over federal lands to states.

Public land issues are of particular concern in the West, where more than half of the land is federally owned, according to 2010 agency data compiled by the nonpartisan Congressional Research Service. More than two thirds of Utah is federal land, making it second only to Nevada, more than 80 percent of which is federal land as well.

Last fall, Utah Attorney General John Swallow argued in an op-ed that the federal government shutdown proved, once again, that such land should be under the control of the states. The state had already passed a measure requiring the federal government hand over public land, but Utah’s own legislative analysts wrote that the measure had “a high probability of being declared unconstitutional.” That measure’s chief sponsor was state Rep. Ken Ivory (R), an ALEC member and ardent proponent of states taking over federal land.

The issue isn’t just a concern of ALEC members. In January, the Republican National Committee adopted a resolution in support of Western states “taking back public lands.”

ALEC’s influence is widespread. Measures modeled off ALEC bills were introduced in at least 34 states during the 2011-2012 legislative session, according to a recent Brookings Institution analysis. Of the at least 132 bills introduced, just 10 percent were sponsored by Democrats.

Criticism of ALEC reached an inflection point in recent years when it was unearthed that the group had supported measures similar to Florida’s “Stand Your Ground” law, which was cited by George Zimmerman in defense of his shooting and killing of Trayvon Martin. In the wake, the group lost a number of corporate members and has backed away from supporting such measures while refocusing on economic and other policies.

Meierling cast that as part of a normal membership ebb and flow and the group still maintains numerous corporate and legislative members.