Trenchless feasibility and suitability assessments have become increasingly important for trenchless projects, as some federal and state permitting agencies have released guidance on the information required to complete their environmental review. The Federal Energy Regulatory Commission (FERC) released guidance in October 2019, and the Pennsylvania Department of Environmental Protection (PADEP) has released a draft trenchless technology technical guidance document for use by project applicants when considering trenchless crossing methods in Pennsylvania. For complex trenchless installations, and for trenchless projects that have multiple permitting agencies with different guidelines, the level of effort and importance of following the guidelines to reduce permitting and project delays has become increasingly important. This paper will discuss the federal, state, and local permitting and regulatory requirements for interstate natural gas pipeline projects and will discuss trenchless technology feasibility and suitability analyses for a natural gas steel pipeline river crossing. The paper will explain the trenchless technology guidelines and discuss their use in selecting the most practical and least impacting trenchless alternative.