### Question
How does the law define challenge cost-share agreement?


### Answer
Under *16 U.S.C. § 1f*, **challenge cost-share agreement** is defined as:

> any agreement entered into between the Secretary and any cooperator for the purpose of sharing costs or services in carrying out authorized functions and responsibilities of the Secretary of the Interior with respect to any unit or program of the National Park System (as defined in section 1c(a) of this title), any affiliated area, or any designated National Scenic or Historic Trail

#### Citation:
  - *16 U.S.C. § 1f*
  - Heading: **CHAPTER 1-NATIONAL PARKS, MILITARY PARKS, MONUMENTS, AND SEASHORES > SUBCHAPTER I-NATIONAL PARK SERVICE**

