Take a ride on this section (left map) of Hwy 89A south of Flagstaff, Arizona on the way to Sedona. You might like a stop at Slide Rock State Park. Here's a link with photos of the park. Here's the AZ State Parks map.
Continue 63 miles from Sedona to Prescott (right map) for more twisties on Hwy 89A after passing the Jerome State Historic Park and the Douglas Mansion, now a museum, in the park. See larger map. The Hotel Connor is rated excellent by Trip Advisor. There may be other riders in town on any given weekend.
"A treasured bit of history traversing a rare and scenic Arizona wilderness, Verde Canyon Railroad is a fresh view into the unspoiled heart of the West. Postcard-perfect scenery is only part of the magic. The train provides a comfortable and exciting journey as it travels a leisurely four hours from the charming Clarkdale depot to the ghost ranch at Perkinsville and back. Awe-inspiring rock formations, historic trestles, ancient cliff dwellings and soaring raptors are just a few of the trip’s many highlights. First-class cars boast plush seating, complimentary appetizers and a full-service bar. Coach offers vintage Pullman-style seating, panoramic windows and snack bars. Everyone has access to open-air viewing cars offering 360-degree views and spectacular photographic opportunities.
A stone’s throw (15 minutes) from the hillside mining town of Jerome, Verde Canyon Railroad’s Clarkdale depot is located in the heart of the Verde Valley, a diverse crossroads featuring amazing adventures in every direction. Only two hours from Phoenix and 25 minutes from Sedona, Verde Canyon Railroad is the perfect Arizona day trip. Reservations are accepted at 800.293.7245 or online at verdecanyonrr.com."
This unpaved switchback is on Hwy 261 north of Mexican Hat, Utah. Here's an excerpt from the review I found on TripAdvisor.
"Highway 261 starts paved from either end but the switchback element is unpaved, well-graded and relatively narrow. Having said that, a brake test beforehand is recommended and don't go too fast as any urgent deceleration could invite an unwelcome skid - it's obviously best to go down with nobody coming up, but an oncoming 'meeting' should be readily negotiable. Sensible driving should make things perfectly safe, unless you ignore the State recommendation of a 28ft maximum vehicle length, 10000lb weight and it's not overly wide; the gradient is advertised as 10%..." See the full review
Arizona DOT has a scenic roads map on pdf you can save or print.
Tonto Natural Bridge State Park (B) north of Payson, AZ may be the largest natural travertine bridge in the world, at 183 feet high spanning a 400-foot long tunnel.
Here's a larger map with directions.
60 miles east of Winslow, just off I-40 and bisected by historic Route 66, is Petrified Forest National Park (D). "Named for its large deposits of petrified wood, the park covers about 146 square miles (380 sq km), encompassing semi-desert shrub steppe as well as highly eroded and colorful badlands. The site, the northern part of which extends into the Painted Desert, was declared a national monument in 1906 and a national park in 1962. About 600,000 people visit the park each year and take part in activities including sightseeing, photography, hiking, and backpacking."
Arizona Hwy 89a crosses the Colorado River at Marble Canyon, Arizona. The 1929 bridge is now a walking bridge with spectacular views of the river.
"It was an historic day when, on January 12, 1929, the bridge was opened to traffic. At the time, it was the highest steel arch bridge in the world and made traveling between Utah and Arizona much easier. No longer did travelers have to contend with the moods of the Colorado River at Lees Ferry. The dedication of the bridge took place June 14-15, 1929. For such an isolated spot, it was an astounding event. Nearly 7,000 people in 1,217 automobiles arrived for the celebration. Speeches were given by the governors of Arizona, New Mexico, and Utah and by the President of the Mormon Church. Bands, choral groups, and Native American dancers were also a part of the festivities. It was reported that airplanes flew under the bridge and as Prohibition was in effect, the bridge was christened with a bottle of ginger ale. The bridge was known as the Grand Canyon Bridge for five years following the dedication. In 1934, after great debate in the Arizona legislature, the official name was changed to Navajo Bridge."