Many of us can identify with explorer William Clark's declaration on reaching the Pacific: "Ocian in view! O! the Joy!" But joy is not all Clark felt upon reaching the beach.

On the Washington side of the Columbia River across from Astoria, you can follow in the footsteps of Meriwether Lewis and Clark as they struggled to complete their westward transcontinental mission in 1805. You can proceed from the cove they called "Dismal Nitch" where they were trapped, soaked, and battered for days by foul weather, move past that body of land they called Point Distress, to wind up where the river meets to ocean on the part of the coast named even before they arrived: Cape Disappointment.

Dismal, Distress, Disappointment. The final stretch of Columbia country took its toll on the weary travelers before they could claim they'd reached the sea.

As historian David Nicandri points out in his new book, River of Promise: Lewis and Clark on the Columbia (The Dakota Institute Press, $18.95 paperback) the declaration of joy by Clark seems a bit forced, and the miseries felt at the expedition's finish seem rather extreme. Nicandri, longtime director of the Washington State Historical Society, offers his careful and deep readings of Lewis and Clark's journals and the diaries and notes kept by their men, in shaping an analysis that throws fresh light on an adventure and its heroes during its historic, though Nicandri believes, under-appreciated trip from the Continental Divide down the Columbia.

River of Promise attempts to redress the balance of Lewis and Clark scholarship, which has tended to focus on the Missouri country portion of their expedition, and to weigh in on scholarly controversies and take some of the shine off the hagiographic halo that still surrounds Lewis and Clark. The mythologizing, Nicandri says, marked the recently passed Lewis & Clark Bicentennial and is evident in the works of such popular storytellers as Stephen Ambrose and Ken Burns.

You would think that after 200 hundred years and countless books, we'd know everything there is to know about Lewis and Clark and their heavily documented travels. But there are many points of disagreement among historians and scholars, some trivial, some not. And careful examination of their manuscripts, revisions, and notes, some written literally between the lines, offer fodder for answering questions. How did the two men get along? What was the source of Lewis' mental breakdown that led him to commit suicide a few years after returning home? What was the real contribution of Sacajawea? At what point did the expedition accomplish its major goals? In fact, something as seemingly simple as when they first saw the Pacific Ocean turns out to be in dispute.

That brings us back to Clark's "O! the joy!" moment, which Nicandri believes was written months after the fact and was not exactly the spontaneous eruption that it sounds. Indeed, the Lewis and Clark journals cannot be read as mere daily diaries written contemporaneously, but in fact were often revised, back-filled, left blank, and composed according to literary and expedition conventions. Throughout their works, Nicandri tracks the influence, and even passages that approach plagiarism, from the journal of Alexander McKenzie's transcontinental journey to the Pacific in Canada. The "O! the joy!" moment might have been genuine, but it was also necessary to any Age of Enlightenment expedition narrative.

Nicandri raises the question of what Clark was seeing when he had his "eureka" moment. There is debate about whether the Pacific can actually be seen from the place where Clark recorded his shout-out, and this, in turn, leads to an interesting discussion about where an ocean begins and a river ends. Anyone who has visited the mouth of the Columbia knows that there is a transition from river to sea, and that ocean storm surges can be carried far up the river. Changing geography at the river's mouth also raises questions. What the debate underscores is how, in the moment, exploration is often unclear, confusing, and mistakes are made. Clark may have seen the actual Pacific, or he might have been fooled by breakers on the river. "O! the Estuary!" doesn't have quite the ring to it.

In contrast, Nicandri points out the almost total silence that accompanied the expedition's real accomplishment at the confluence of the Snake and the Columbia rivers back upstream. Here, Nicandri argues, was the real moment of accomplishment for they had finally found the Columbia, the Great River of the West that no white men had followed before, save probing its mouth. Yet instead of exultation, the explorers were silent or seemed to sulk.

One reason was that it was at this moment that they discovered that the river they had been following, the Snake, was not the Columbia itself (they thought it was) and that their previous maps and conceptions would all need to be revised. Second, it also meant that the purpose of their trip, to find an interior water route to the West that connected the Missouri and Columbia, was foiled by actual geography. There were many rivers and many mountains that interrupted the flow of waters, and progress. Their Northwest Passage did not exist.

Therefore, as they slouched to the coast, Lewis had stopped keeping his journal, >they suffered from nasty winter weather, and health and morale had taken a beating. Clark seems the stalwart who held things together, Lewis studied and botanized, but also turned a bit Captain Queegish on the expedition's return trip. Scholars speculate about the causes of his breakdown: malaria, syphilis, manic depression, or plain old depression. Given the hardship all endured, it's amazing more of them didn't go mad.

Nicandri believes Lewis suffered from post-traumatic stress disorder, the result of command, privation, illness, injury (one of his own men accidently shot him in the buttocks), and disappointment. Despite all that the explorers had learned and the value of their trip, they were going to have to go back and tell their boss and patron, Thomas Jefferson, that the American West was not exactly what he'd hoped.

River of Promise is a book for readers who already have some familiarity with Lewis and Clark. Nicandri's reading is at times nitpicky, at others speculative, but he brings a refreshing perspective and good advice: to read the expedition journals in context, to not take them at face value, to look at the details for fresh insights. He notes, for example, that on their return along the Columbia, Lewis grows increasingly frustrated by encounters with Indians who harass his men, throw stones, and behave in an unfriendly manner. But Nicandri notes that many of these instances follow Lewis' venturing into Indian burial grounds and poking around, recording Native American funerary customs.

Many tribes along the Columbia and elsewhere understood that when an outsider visited a grave site without permission, it was a sign of hostility (many tribes still feel that way). For all their care at respecting native welcoming rites and smoking ceremonies, and for attempting to allay Native fears with trade and signs of peace, Lewis and Clark seemed clueless about this connection of native "bad" behavior and their own unintentionally boorish ways.