Holly Neill fought fire for the National Park Service, U.S. Forest Service and private contractors for twelve seasons, from 1995 to 2007. Her federal experience includes work on engine and helitack crews, Incident Command Post radio operator, and Fire Use Module member. Her contract experience includes safety liaison for a federally contracted timber faller organization and B certified contract faller.

Neill is a research specialist and consultant on the Yarnell Hill Fire and the tragic deaths of the 19 Granite Mountain Hotshots on June 30, 2013. She seeks answers to many questions left unanswered by the two official reports, by doing data research, conducting interviews, visiting the fire site and related places, and collaborating with Granite Mountain Hotshot family members and others involved in the fire. She believes that a more complete, accurate and lasting factual legacy can and will be left to the GMIHC and their families, one that can stand the test of time. Firefighter safety and lessons learned can only benefit by a full accounting of the decisions made on the fire and who made them, and most importantly an explanation of why they were made.

Neill also acts as a research partner for author John Maclean, who is working on a book about the Yarnell Hill Fire.

Neill is a founding member of Safety Matters: A Wildland Firefighter Forum for Change, a group of fire veterans advocating for wildland firefighter safety. The group, which calls attention to deficiencies in wildand firefighter safety in current wildland fire management systems, encourages firefighters, the public, and their representatives to support and demand changes in policy and practices so that wildland firefighter and public safety is truly the first priority in all fire management actions.