SCENIC DRIVE

and bear right before dipping through a thistle-lined wash. Soon after, you'll make your closest approach to the south face of the cinder cone. SP Crater erupted thousands of years ago but has resisted erosion - in part, geologists say, because of an agglutinate, or glued-together, rim that protects its structure. About a mile later, you'll notice Colton Crater - another cinder cone, but older and wider than SP Crater - to the south. You'll soon begin following a fence on the left side of the road. Then, at Mile 8.2, go right at yet another fork. You'll head north for a couple of miles; at Mile 10.4, go right at one last fork, onto a short road that quickly merges with a wider route. There aren't any forks the rest of the way, so as you head east, you can just enjoy the scenery. On the north side of SP Crater, that scenery includes the dis-tinctive lava flow, which you'll cross around Mile 12.

The flow extends some 4 miles to the north and is 100 feet thick in places. Lava from cinder cones often flows from breaches in their sides, as apparently happened here. Estimates vary on this lava's age, but some scientists say it's more than 70,000 years old. But that's young compared with some other cinder cones in the San Francisco field, which saw its first volcanic eruptions about 6 million years ago. From the lava flow, it's another 7 miles east to U.S. 89, where you'll find yourself about 2 miles north of where you started the drive. For a bit more volcanology, stop at Sunset Crater Volcano National Monument on your way back to Flagstaff. Unless, of course, you're ... pooped.

ADDITIONAL READING:

For more adventure, pick up a copy of our book Arizona Highways Scenic Drives, which features 40 of the state's most beautiful back roads. To order, visit www.shoparizonahighways.com/books.

TOUR GUIDE

Note: Mileages are approximate.

LENGTH: 19 miles one way (from U.S. Route 89) DIRECTIONS: From Flagstaff, go north on U.S. Route 89 for 27 miles to an unmarked road on the left (it's just before Milepost 446 and Hank's Trading Post). Turn left (west) onto the unmarked road and continue 0.5 miles to a fork. Bear left at the fork and continue 4.2 miles to another fork. Bear right at the fork and continue 3.5 miles to yet another fork. Bear right at the fork and continue 2.2 miles to one more fork. Bear right at the fork and continue 0.1 miles to a wider road. Merge onto the wider road and continue 8.5 miles back to U.S. 89.

VEHICLE REQUIREMENTS: A high-clearance vehicle is recommended, but the route is passable in any vehicle in good weather.

SPECIAL CONSIDERATIONS: The route is open to the public but is on Babbitt Ranches property. Please be considerate, and do not take lava rocks or other souvenirs.

WARNING: Back-road travel can be hazardous, so be aware of weather and road conditions. Carry plenty of water. Don't travel alone, and let someone know where you are going and when you plan to return.

INFORMATION: Babbitt Ranches, 928-774-6199 or www.babbittranches.com Travelers in Arizona can visit www.az511.gov or dial 511 to get information on road closures, construction, delays, weather and more.