Pursuant to a congressional request, GAO reviewed the Forest Service's implementation of certain unilateral modifications to long-term contracts in Alaska and other requirements of the Tongass Timber Reform Act, focusing on whether: (1) road credits are used consistently between long-term contracts and short-term contracts; (2) buffers of standing timber have been left along designated streams as required; and (3) the Forest Service is requiring full documentation of environmental effects whenever changes are made to timber harvest area boundaries. GAO found that: (1) the Forest Service believes it treats road credits consistently across all contracts, since unused road credits are cancelled at the end of all timber sales contracts; (2) the long-term contractors' ability to carry unused road credits forward for longer periods than short-term contractors gives them an unfair competitive advantage; (3) some streamside buffers did not meet the 100-foot minimum width during the first years immediately following the act's passage, but the Forest Service has since taken steps to enforce this requirement; (4) in 1994, the Forest Service issued guidance and initiated a new monitoring program to ensure the buffers' effectiveness; (5) the Forest Service often does not document the environmental effects of timber harvest boundary changes; (6) in some instances, the forest supervisor has inappropriately delegated his documenting authority to district rangers and waived documentation where he believed boundary changes were insignificant; and (7) the forest supervisor has since withdrawn the authority delegation and established a detailed process for assessing boundary changes.