As of the end of 2003, there were up to 200,000 illegal immigrants in Canada (most residing in Ontario). Most are refugee claimants whose refugee applications were rejected by the Immigration and Refugee Board of Canada. There are very few illegal immigrants who enter the country without first being examined by the CBSA. The reason for this is that Canada is physically very difficult to get to, with the exception of crossing the Canada/U.S. border. As the U.S. is itself a prime destination for illegal immigrants, not many illegal immigrants then attempt to cross the border into Canada in the wild.