In Yukon, Hanson first worked as a regional social worker for the Department of Indian and Inuit Affairs, with a region that spanned from Old Crow, Yukon to Good Hope Lake, British Columbia. She subsequently worked for INAC in Nanaimo, British Columbia and in Ottawa, returning to Yukon in 1989 to lead a federal self-government negotiations team. She served as Yukon Director of Land Claims and Indian Government for the federal government until 2003, when she became the regional director general of Indian and Northern Affairs Canada in the Yukon, charged with reorganizing the department's regional presence to reflect the federal presence "post land claims and devolution". She retired from this position in 2007. Hanson and her family completed a federal interchange to Canberra, Australia, with the Aboriginal and Torres Islander Commission. She owns a property at Crag Lake, Yukon  After her retirement from INAC, Hanson became actively involved with the Yukon New Democratic Party and became president of the party. On September 26, 2009, Hanson was acclaimed as leader of the Yukon NDP, following the resignation of previous leader Todd Hardy, who had resigned due to an ongoing struggle with leukemia. Following Hardy's death on July 28, 2010, Hanson won the resulting by-election on December 13, 2010 in Whitehorse Centre by a large margin. She retained her seat comfortably in the 2011 election, leading the Yukon New Democrats from third party status to Official Opposition, with six of the legislature's 19 seats. During both the 32nd and 33rd Legislative Assemblies, Hanson served on the Members’ Services Board and the Standing Committee on Public Accounts. She Chaired the Standing Committee on Public Accounts in the 33rd Legislative Assembly (2011-2016). Hanson sought re-election again in 2016 election, and although she was narrowly successful in her own riding, Hanson's party lost four of its six seats to the Yukon Liberals and was reduced to third party status - it was also the Yukon New Democrat's worst electoral showing since 1978. The Yukon Liberals, formerly the Third Party, formed a majority government. Hanson has stayed on as New Democrat leader since the election. She is currently a member of the Members' Services Board, the Standing Committee on Public Accounts, and the Standing Committee on Rules, Elections and Privileges. Additionally, she serves as the New Democrat caucus critic for the Department of Finance, the Executive Council Office, the Department of Energy, Mines and Resources, the Department of Economic Development, the Department of Justice, the Department of Highways and Public Works, the Public Service Commission, the Department of Tourism and Culture, the Yukon Workers Compensation Health and Safety Board, and the Yukon Liquor Corporation.