The current route starts at US 60 in Globe and runs through the San Carlos Indian Reservation, Safford and Duncan into New Mexico near Virden.

Shortly after leaving town, SR 77 splits off and heads south towards Tucson, while US 70 continues southeast, then east, entering the San Carlos Indian Reservation.

The highway parallels the Arizona Eastern Railway to Cutter, where the railroad curves northeast towards San Carlos.

From this point, US 70 continues east through isolated rolling hills, surrounded by mountains and thick desert brush.

Past the interchange, US 70 crosses over the Arizona Eastern Railway and San Carlos River into Graham County.

Approximately 21 miles (34 km) east of Peridot, US 70 crosses the Gila River over a bridge before meeting Coolidge Dam Road (BIA 3) at an intersection near Calva.

Southeast of the Coolidge Dam intersection, US 70 leaves the rugged stark terrain and enters the farmlands of the Gila River valley.

The highway then heads east through the rural communities of Bylas and Fort Thomas before reaching the town of Pima.

East of Safford, the Globe branch of the Arizona Eastern Railway splits off from US 70 for the last time, heading southeast towards Bowie.

Sanchez Road in Solomon provides access to Safford Regional Airport, just north of the small community.

San Jose is home to the Safford State Prison, located just northeast of current US 70 and US 191 on Old Highway 70.

US 70 proceeds east through flat empty terrain, before entering a small range of mountains, where it crosses into Greenlee County.

Upon exiting the mountains, US 70 meets the Gila River and a different branch of the Arizona Eastern Railway in the town of Duncan.

At Main Street, US 70 serves as the southern terminus of SR 75, which proceeds north, following the Gila River to Three Way.

[4] Earlier in the highway's history, US 70 was designated further north than it is now, and served a small area of northeastern Arizona.

[5][7][2] U.S. Route 180 (US 180) was the original U.S. Highway designation between Globe and the New Mexico state border near Virden.

Due to the popularity of the Lee Highway, the state-designated Roosevelt Dam name became largely forgotten by the traveling public.

By this point, a previously existing more direct route between San Jose and Duncan had been added as a branch of the Rice–Safford–Duncan Highway.

The purpose of the dam was to help solve water issues plaguing the Apache people living within the San Carlos Indian Reservation.

Water retaining began on November 15, 1928, and was placed under management of the San Carlos Project, a division of the Bureau of Indian Affairs (BIA).

[10] At first, construction of the dam faced massive opposition from the Apache Nation as a tribal burial ground was within the area of the proposed reservoir.

The section of former US 180 between Rice and a point northwest of Geronimo was abandoned from the state highway system.

[12] Due to limited state funding, the new alignment wasn't paved, but was instead oiled down to provide some stability and rigidity.

When US 60 was extended west to California through Arizona the same year, both highways shared a concurrency between Globe and the US 180's western terminus in Florence Junction.

The route started at US 66 in Holbrook, and ran south to Concho, then east to St. Johns, where the highway turned south again to Springerville, then due east into New Mexico to Clovis, and eventually, its eastern terminus in Beaufort, North Carolina.

This not only moved the western terminus of US 70 from El Paso to California, but also reintroduced US 70 to the state of Arizona after 4 years of absence.

[7] Some adjustments were made to the new routing of US 70 between 1935 and 1936, moving the highway between Hondo and Lordsburg in New Mexico further south through Alamogordo, Las Cruces and Deming.

[30] On June 21, 1937, SR 77 was extended south to Oracle Junction, establishing a short concurrency with US 70 between Globe and an intersection just west of Cutter.

The new route was proposed to run around the north side of the San Carlos Reservoir and bypass the Coolidge Dam.

The Cutter to Peridot project along with the remaining proposed route was estimated to cost a total of $6 Million when complete and would eliminate 11 miles off the length of US 70.