Target offers funding for field trips (up to $800) for 5,000 classes this next year.
The Target Field Trip Grants program provides funds for K-12 field trips in
order to give students throughout the country the opportunity to explore more of
the world outside the classroom. For the 2009-2010 school year, 5,000 grants of
up to $800 each will be awarded to educators, teachers, principals,
paraprofessionals, and classified staff who are employed by accredited K-12
public, private, or charter schools. Types of eligible field trips include art,
science, and cultural museum visits; community service and civic projects; and
career enrichment opportunities. Funds may be used to cover trip-related costs
such as transportation, ticket fees, resource materials, and supplies. Online
applications will be available from August 5 through November 3, 2009.
You would not receive these funds directly, but you could use this information to target schools in your area (and beyond) to attend your historic site. This is a great reason to contact local principals, school districts, and teachers to remind them about your programs and how they CAN afford to attend a field trip at your location. As mentioned, they would receive the funds directly, but if you charge admission, the grant could cover that.
More information is on the Target webpage.