Colorado Republican Jane Norton raised more than a half-million dollars in her first 16 days as a challenger for the Senate seat that Democratic incumbent Michael Bennet is defending.

Norton, a former lieutenant governor, will file a report showing she raised $506,000 between Sept. 15 — when she announced her candidacy — and the end of the month, the cutoff for this year’s third-quarter filing period. Detailed campaign reports must be filed with the Senate Office of Public Records in Washington by Oct. 15.

Norton’s campaign said that it received contributions from 587 donors, for an average of about $860 per donation, and that the total reflected “tremendous financial support” for her campaign.