Several years ago, Noble Energy migrated its Gulf of Mexico investments to deepwater where our activities are driven by exploration. Our focus is on high-impact opportunities with the potential to provide significant medium and long-term growth to the Company. With a track record of success in finding and developing crude oil and natural gas resources, we have several large producing fields, multiple ongoing development projects and a substantial inventory of additional exploration opportunities.
First production from Galapagos (Isabela, Santa Cruz, and Santiago) was achieved in 2012 with initial production rates exceeding expectations. Additional recovery potential and multiple follow-on opportunities increase Galapagos total resource potential to 250 MMBoe, gross.
Gunflint, a 2008 discovery and Big Bend, a 2012 discovery, were sanctioned in 2013 and will provide the next leg of production growth for our deepwater Gulf of Mexico business. Big Bend, as part of the Rio Grande complex, will initially be a 1-well tieback with first production estimated in late 2015. Successes at Troubadour and Dantzler increase gross discovered resources of Rio Grande to 140 to 240 MMBoe. Dantzler is planned as a two-well tie-back, utilizing Big Bend infrastructure, with initial startup in 2016. Gunflint is planned to be a 2-well tieback to come online in mid-2016. Combined, these fields are planned to double the Company's deepwater Gulf of Mexico production over the next four to five years.
With an unrisked exploration inventory of over 3 billion barrels of oil equivalent gross, we maintain a multi-year inventory of prospects focused on subsalt Miocene and proven amplitude plays. Multiple new prospects are targeted annually. In 2014, we announced a discovery at the Katmai exploration prospect which provides another major project development for the Company.