2012—Subsec. (d). Pub. L. 112–141 inserted “, which may include electric vehicle charging stations or natural gas vehicle refueling stations,” after “parking areas”.

1991—Subsec. (c). Pub. L. 102–240 substituted “$50,000” for “$15,000” wherever appearing.

1968—Subsec. (c). Pub L. 90–495 increased from $10,000 to $15,000 the cost limitation on construction per mile, or per project for projects of less than a mile, which the Forest Service may construct on its own account and struck out provisions spelling out the functions which the Secretary of Agriculture is authorized to perform in carrying out such construction.

1964—Subsec. (a). Pub. L. 88–423 inserted “and other” after “experimental”.

1960—Subsec. (a). Pub. L. 86–657 substituted “may enter into contracts” for “may enter into construction contracts”.

Amendment by Pub. L. 112–141 effective Oct. 1, 2012, see section 3(a) of Pub. L. 112–141, set out as an Effective and Termination Dates of 2012 Amendment note under section 101 of this title.

Amendment by Pub. L. 102–240 effective Dec. 18, 1991, and applicable to funds authorized to be appropriated or made available after Sept. 30, 1991, and, with certain exceptions, not applicable to funds appropriated or made available on or before Sept. 30, 1991, see section 1100 of Pub. L. 102–240, set out as a note under section 104 of this title.

Amendment by Pub. L. 90–495 effective Aug. 23, 1968, see section 37 of Pub. L. 90–495, set out as a note under section 101 of this title.