The geology books say that every mile you go downstream from Rome on the Owyhee River, the rocks around you get 100,000 years older.

What our group was hoping, though, was that every mile would add about 10 degrees to the air temperature.

We woke early last May in the Bureau of Land Management's campground outside of Rome to frost on our raft frames and icicles hanging from the sprinkler lines in the adjacent fields.The setting-off point for one of Oregon's most remote and rewarding river destinations, Rome is little more than a Pepsi sign along U.S. 95 in the vastness of Oregon's outback.

But there are good, greasy potatoes and hot coffee at the Rome Station RV and Cafe, the only business around. So after a few "when in Rome" jokes, we rigged our rafts and prepared our kayaks for the four-day, 48-mile float down to Birch Creek.

This portion of the Owyhee isn't known for continuous white-knuckle whitewater -- the most difficult rapids, like Whistling Bird or Montgomery, are Class IV or below -- so it's important to make the most of the scenic and cultural side trips.

At first the lower Owyhee looks like little more than an overgrown irrigation ditch, diked and surrounded by agricultural fields. But soon the river begins to split, meander and braid through the high desert, and the eroded white formations rise near where Jordan Creek enters on the right.

The Owyhee River from Rome to Birch Creek

Because of the fickleness of flows in the river, the rafting season on the Owyhee is extremely short -- usually March to May -- if there is one at all.

This year, based on snowpacks of 80 to 100 percent of normal, the Bureau of Land Management recreation staff is projecting that raftable water levels should hold through early May, and they're hopeful that the season could run all the way till Memorial Day.

Information on floating the Owyhee, rules, logistics and maps can be found at the BLM's site, http://tinyurl.com/cxa7gs, or call 541-473-3144.

For flow information, check the Willamette Kayak and Canoe Club's river levels Web site, www.wkcc.org/levels. Rafters generally like a flow of at least 1,000 cfs, measured at Rome.

The rocks of the Owyhee basin are generally made up of layers of sedimentary rocks from ancient lake basins or plains, interspersed with dark bands of volcanic flows, according to Elizabeth and William Orr's wonderful "Rivers of the West: A Guide to Geology and History."

The Orrs explain that the river's drop carries you through rocks from 10 million years old in Rome to roughly 16 million years below Birch Creek.

And once out of the valley of Rome, we begin to see the "swirled flow banding like a marble cake," as the Orrs describe the pinkish rhyolite common to the basin.

Farther on, the river goes into sheer-walled canyons, like Green Dragon Canyon, where a brightly colored kayaker is a blip at the base of the red and gray rock walls.

A few more bends and you're back in an open section, where yellow mule's ear, desert primrose and Indian paintbrush mix with the bunchgrass and sage on gentler slopes.

"Some of the scenery can hold its own for awesomeness with most any place in the world," wrote Mike Hanley in his book, "Owyhee Trails: The West's Forgotten Corner."

And by the end of our first day, we were able to enjoy the scenery in the warm sun. Even as we moved farther back in time, it seemed we were moving forward from spring to summer.

We spent an afternoon soaking in a hot spring just above a riverwide wave well-suited for surfing kayaks or even rafts. A later day hike took us to a view point of the dramatically eroded ramparts of Pruitt's Castle, whose spines of tufted white rock are cut by black and brown bands of lava.

It was a view that definitely held its own for awesomeness.