Logan Simpson completed biological resources technical studies for the proposed 225-mile Lake Powell Pipeline. The project included the construction and operation of a buried water pipeline, water intake facility at Lake Powell, surface water storage reservoirs, hydro-electric generation facilities, and transmission lines. The pipeline corridor included federal, state, private, and tribal lands extending from Glen Canyon Dam, Arizona to Cedar City, Utah. Logan Simpson: completed 386 miles of field surveys documenting 16 special-status plant species occurrences of over 350,000 plants; mapped the distribution of 17 species of noxious/invasive weeds; recorded 306 plant taxa; and documented 3,443 polygons representing 556 vegetation associations on 25,000 acres. As alignments shifted, we assessed which rare plants potentially occur and adjusted survey schedules to match phenology of the target plants in target areas to aid in surveys and positive identification. A geospatial database of the vegetation survey results was developed to provide the basis for impact analysis of rare plants, determine mitigation actions, and develop an invasive/noxious species management plan.