Section 106 of the NHPA requires the BLM to consider the impacts of its actions on historic properties and to seek comments from the State Historic Preservation Office (SHPO) and the Advisory Council on Historic Preservation (BLM Manual Section 8143.06). In fact, federal agencies are required to take into account the impact of any federally assisted or federally licensed undertaking on properties included on, or eligible for inclusion on, the National Register of Historic Places (NRHP). These responsibilities are the same on split-estate land as on public land (BLM Manual 3101.9). The 1992 amendments to the NHPA replaced the definition of “undertaking” in Section 301 of the Act as follows:

“Undertaking means a project, activity, or program funded in whole or in part under the direct or indirect jurisdiction of a federal agency, including:

If activities to be conducted on split-estate lands under the terms and conditions of a federal oil and gas lease would result in adverse impacts to historic properties, the BLM has the authority to impose appropriate avoidance or mitigation measures. Currently, the BLM authorized officer consults with the SHPO to identify and evaluate historic properties that might be impacted, to assess impacts, and to determine satisfactory means for avoiding or mitigating adverse impacts. The Advisory Council on Historic Preservation is then given the opportunity to comment only if listed or eligible properties would be impacted. This process is explained in more detail in a current agreement among the Advisory Council, SHPO, and the BLM (regulation guidance is found in 36 CFR 800).

The BLM Manual 8100 (including the Wyoming manual supplements) contains guidance, policy, and the extent to which the BLM is responsible for split-estate land. It also indicates direction when access is denied to an operator or BLM personnel in determining impacts pursuant to the NHPA. Key points in the manual are that (1) any historic properties encountered belong to the landowner and if the landowner wishes, any cultural material removed from the property should be returned after study; (2) the authorized officer must consider alternatives if the landowner continues to refuse access for cultural resource work, including the feasibility of relocating the project; and, (3) the authorized officer also may consider approval or denial of the application without the cultural resource information. The other avenue for access is by way of the courts and is addressed under “Access to Develop Federally Owned Minerals.”