Some important essential oil guidelines to remember: Essential oils should be diluted in a carrier oil to a maximum of 5% (see these 5 Face Oils For Naturally Clear, Flawless Skin and The Best Face Oils By Skin Type). So since 1 ml is 20 drops, for every 1 ml of carrier oil, you would add 1 drop of EO.
The San Francisco Peaks are composed of six peaks, including the four highest in Arizona: Humphreys Peak, 12,637 feet (3,851 m), Agassiz Peak, 12,356 feet (3,766 m), Fremont Peak, 11,969 feet (3,648 m), Aubineau Peak, 11,838 feet (3,608 m), Rees Peak, 11,474 feet (3,497 m), and Doyle Peak, 11,460 feet (3,493 m).
Interstate 40 is a main route to the South Rim of the Grand Canyon, with the exits leading into Grand Canyon National Park in Williams and Flagstaff. I-40 covers 359 miles (578 km) in Arizona. Just west of exit 190, west of Flagstaff, is its highest elevation along I-40 in the US, as the road crosses just over 7,320 feet. I-40 also passes through the Navajo Nation, the largest Indian reservation in the US.