Denver No. 2 Ultra-Low Sulfur Diesel
This link will direct you to the 2017 Spec book's "Denver No. 2 Ultra-Low Sulfur Diesel" website.
The link address is: https://www.codot.gov/business/designsupport/cdot-construction-specifications/2017-construction-standard-specs/fuel-cost-adjustments/opis_denver_ultra_low_sulfur_diesel_lub/daily_prices