Assemblywoman Peggy Pierce of Nevada said undocumented immigrants do not receive Social Security, food stamps or Medicaid in her state - but that has not deterred them from coming.

''Certainly no one would accuse us of being generous or overly generous, and there are a lot of folks moving to our state,'' she said during the conference co-sponsored by the Colorado Legislature and the nonpartisan National Conference of State Legislatures.

According to the NCSL, state legislatures considered close to 300 immigrant and refugee bills during the first half of this year on everything from benefits, education and employment to human trafficking, identification and law enforcement. The NCSL said 36 bills were enacted into law.

''In the past several years, we've seen more and more legislation as frustration rises among the public,'' said Ann Morse, an immigration policy analyst for NCSL.

Lawmakers from Colorado, Utah, Nevada and Arizona suggested they were frustrated over a lack of consensus on how to deal with those problems.

Susan Martin, executive director of the Institute for the Study of International Migration and a former director of the U.S. Commission on Immigration Reform, said states are not equipped to enforce federal law and she warned that a patchwork of state immigration laws will only confuse matters.

''I get nervous if you spread this out among state and local authorities. I get very nervous about local cops trying to figure out if people were here illegally or not,'' she said.

Martin said of 200 million migrants around the world, 35 million have come to the United States, and another million are added each year. Of the estimated 11 million migrants who are here illegally, she said, 7 million have jobs.

Rep. Russell Pearce, a Republican from Mesa, Ariz., said local authorities have a duty to enforce the law. He said states should not point their fingers at the federal government.

''We're a nation of laws, and we must demand that our laws be enforced,'' he said.

Beginning in January, Arizona's Legislature will consider proposals to punish employers who hire illegal immigrants; fund a new 50- to 100-person squad of the state police to crack down on border problems; and prohibit immigrants from receiving state-funded job training.

Colorado House Speaker Andrew Romanoff, D-Denver, said he expects a number of bills next year from state lawmakers in three categories: restricting state services for undocumented aliens, sanctioning employers who hire undocumented workers and making the federal government pay.