Dennis won two stages, claiming a lead he didn’t drop after finishing first on Stage 4, and also claimed two runners-up spots and the king of the mountains title.
The 25-year-old finished in the main pack on the final stage from Golden to Denver in Colorado to take the overall title by 40 seconds ahead American team-mate Brent Bookwalter.
"I had a lot of fun this week and hopefully I can come back next year and do it again," Dennis said. "I have to take my hat off to the team. They never put any pressure on me. I came here to help Brent originally, then found my legs, and ended up taking the yellow jersey. I have to thank him for quietly supporting me for the general classification."
Dennis's victory was the BMC Racing Team's 31st of the season, bettering the team-record 30 victories achieved in the 2013 and 2014 seasons. It was also the ninth win in nine days for the team that had won the USA Pro Challenge with Tejay van Garderen the past two years.
Dennis has six individual victories to his credit this year, including a win in the opening stage time trial of the Tour de France. He also had a hand in team time trial wins at the Tour de France and the Critérium du Dauphiné.
"We had a couple days of training before the race and saw how strong Rohan was and how well Brent was riding," BMC Racing Team Sport Director Jackson Stewart said.
"We knew Rohan would be really strong in Friday's time trial, but to finish first and second overall this week? I don't think anyone had planned for that. So to have it happen was great."
Bookwalter’s performance and that of team-mate Taylor Phinney ensured BMC took home the team title for the third straight year. With another Australian, Richie Porte, set to join in the near future, from Team Sky, things are certainly looking good for the outfit.
Bookwalter has finished runner-up in two other week-long stage races since joining the BMC Racing Team in 2008, and called this week’s effort it the best performance of his career, highlighted by his solo win on Wednesday’s (AEST) mountain-top finish at Arapahoe Basin.
"Personally, it was a good, diverse week for me," he said. "But really, the highlight was the way the team rode. It was a team effort from everyone like the young guys - Manuel Senni and Kilian Frankiny - to our road captain, Michael Schär - to Rohan and me, Taylor, Pete Stetina and Damiano Caruso - who are some of the more experienced guys. Everyone was doing their job and having a lot of fun doing it."
American Kristin Armstrong, the two-time Olympic time trial gold medallist and riding in her second comeback, earlier captured the three-stage women's race in Golden by 29 seconds over compatriot Tayler Wiles of DNA Cycling.