______
Please confirm current identification requirements with
the U.S. State Department --
www.travel.state.gov
or with the U.S. Department of Homeland Security -- www.dhs.gov
prior to embarking on a cross-border trip with Build A Miracle.
U.S. citizens can also apply for a U.S. Passport Card which facilitates entry and expedites processing at U.S. land and sea
ports-of-entry when arriving from Canada, Mexico, the Carribean, and Bermuda.  The card may not be used to travel by air.  
Otherwise, it carries the rights and privileges of a U.S. passport.  
http://travel.state.gov/travel/cbpmc/cbpmc_2223.html
From the U.S. Department of State's website
This page was last updated on
September 11, 2008
Land/Sea Travelers
Passports required to cross US/Mexico border
as of June 1, 2009
This information is valid as of May 24, 2009.
San Diego Union-Tribune
Border Crossing Changes
March 2009
Build A Miracle
Build A Miracle
Build A Miracle
Build days in Mexico
Newspaper article
On June 1, 2009, the U.S. government will implement the full requirements of the land and sea phase of WHTI (Western
Hemisphere Travel Initiative). The proposed rules require most U.S. citizens entering the United States at sea or land ports of
entry
to have a passport, passport card, or other travel document approved by the Department of Homeland Security.
CHILDREN: U.S. citizen children under the age of 16 will be able to present the original or copy of their birth certificate, or
other proof of U.S. citizenship such as a naturalization certificate or citizenship card.
Groups of U.S. citizen children ages 16 through 18, when traveling with a school or religious group, social organization, or sports
team, will be able to enter under adult supervision with originals or copies of their birth certificates or other proof of citizenship.