Bicycle Route 66 does not always follow Historic Route 66. Deviations were made based on present-day conditions. Many miles of the route parallels interstates. When the interstate system was built, U.S. 66 became I-55, I-44 and I-40 so you?ll ride on interstate shoulders and multiple frontage roads. Between Gallup, New Mexico and Oatman, Arizona the country is open and semiarid; there are generally long distances between services provided by the few trading posts along I-40. Traffic on I-40 is fast and can be heavy due to it being a major east/west truck route. Shoulders are generally wide with well-placed rumble strips, but conditions may vary. Between Gallup and Chambers the route crosses the Navajo Nation and is subject to the rules and regulations of both the U.S. and the nation. The Petrified Forest National Park offers a welcome diversion from riding the shoulder of I-40. The elevation and traffic increase between Winona and Flagstaff. Expect more traffic and urban riding through Flagstaff. Towns increase in frequency beyond Flagstaff. From the I-40 crossing to Oatman there is gradual climbing across the basin for approximately 15 miles. It is followed by 9 miles of steep, narrow ascents around switchbacks to the expansive Sitgreaves Pass before winding downhill into Oatman. In Oatman you can enjoy a trip back to the Old West but don?t feed the wild burros ? they?ve been known to follow and harass bicyclists.