Tomorrow marks the 200th anniversary of Lewis and Clark's triumphant return to St. Louis from their "Journey of Discovery" to the Pacific Ocean. What the famed explorers and their team, the Corps of Discovery, accomplished during the journey -- which spanned 864 days and covered more than 5,000 miles -- was nothing short of extraordinary, and it is definitely worthy of celebration for its historical significance alone.

But I am of the opinion that the expedition is worthy of review for more practical reasons. I believe that many of the keys to Lewis and Clark's success can also be applied by investors to achieve success in the stock market. Three principles, in particular, stand out: preparation, diversity, and risk-taking.

Prepare for your journey first
The roots of Lewis and Clark's success can actually be traced back to 1803, a full year before Meriwether Lewis departed from Washington, D.C., when he began doing his due diligence and readying for his trip in earnest.

At President Thomas Jefferson's request, Lewis traveled to Philadelphia to bone up on his knowledge of medicine, plant biology, and navigation, as well as to interview some of the best minds of the era about what might lie west of the Mississippi river.

This extensive investment in preparation reaped extraordinary dividends throughout the voyage, as time and again Lewis and Clark were called upon to utilize their newfound knowledge in order to help their team navigate the treacherous and unfamiliar new terrain.

In the investing world, individual investors must do a comparable amount of homework before venturing into unknown areas. Be it electronic commerce, biotechnology, nanotechnology, semiconductors, alternative energy, or some other new field, the competitive landscape of any emerging industry is incredibly complex, and they are often populated with vastly different and rapidly changing technologies.

To prosper, it is essential not only for investors to do their own due diligence on these sectors prior to making an investment -- they must also tap into the wisdom and work of those who have spent a good deal of their time thinking about and researching what might lie beyond the horizon. (One group I personally tap into is the staff of the Motley Fool Rule Breakers newsletter.)

These steps alone won't guarantee that an investor will be able to safely navigate around a to find an or an eBay, but it will dramatically increase the odds.

And build a diversified platform
The second key to the explorers' success lay in the incredible diversity of their team. Lewis and Clark, while possessing a myriad of talents themselves, were smart enough to recognize that over the course of an expedition of the type they were undertaking, it was unlikely they possessed all of the requisite skills.

As such, they hired individuals with a wide range of skills, including navigation, fishing, cooking, scouting, sharp-shooting, and mountaineering, among others.

This diversity ensured that when the Corps of Discovery encountered wild animals, wild rivers, rugged terrain, inclement weather, or steep mountains, they had the necessary skills to survive. And it was indeed fortunate that they possessed every one of these skills, because the team encountered all of the aforementioned obstacles at one time or another during their journey.

The analogy is directly applicable to the need of individual investors to maintain a diversified portfolio. For instance, just because you are personally comfortable with, and knowledgeable about, a particular sector - say, retailing -- that does not mean it is prudent to put your entire portfolio in stocks such as Target or Wal-Mart.

The latter would be the equivalent of William Clark thinking that his superior boating skills would alone ensure success. They were important, of course -- but they were useless when the team was crossing the snowy Rocky Mountains.

In this way, the tough stretches that your portfolio will inevitably encounter over time can more easily be weathered. The odds of successfully navigating through difficulty increase greatly if you are balanced across several sectors.

But be willing to chart a new course
One of my favorite stories about Lewis and Clark's journey occurred when the team encountered a fork in the Missouri River. They didn't know which fork represented the true Missouri River. It was critical that they guessed right, because if they pursued the wrong river and had to reverse course, it was unlikely that they would have gotten over the Rocky Mountains before winter set in and, therefore, the success of the entire expedition would have been seriously jeopardized.

Being the good leaders that they were, Lewis and Clark first sent separate teams to explore the two forks. Upon arriving back from their scouting trips, the members remained undecided about the correct route. Over time, however, a consensus among the 30 members of the Corps of Discovery began to emerge.

They reasoned that since the Missouri had been "slow, brown and muddy" up to that point in the expedition, and because the north fork was now "slow, brown and muddy," it had to be a continuation of the river. In this way, that conclusion was the equivalent of those who say that tomorrow will look just like yesterday because "that's the way it has always been."

Lewis and Clark, to their immense credit, reasoned otherwise. They recognized that at some point the snow off the Rockies had to melt, and when it did the ensuing river water would be clear, cold and fast -- the very characteristics of the south fork.

In the face of overwhelming opposition, the two overrode their team's objections and ordered them down the south fork. It was the correct decision.

The relevance of this little story is that many investors -- like the majority of the Corps of Discovery -- will believe that "tomorrow is going to look just like today."

Personally, I don't believe this is the case. As a result of the work that Genentech (NASDAQ:DNA) is doing in the field of DNA sequencing, Toyota (NYSE:TM) is doing in robotics, and GE (NYSE:GE) is doing in alternative energy -- as well as the exciting and innovative work taking place in the hundreds of "rule breaking" companies around the globe -- we have now arrived at a comparable "fork in the river."

The future is going to be significantly different from what most people believe, and to succeed, investors must be willing to chart a new course -- even when it appears risky. From my perspective, however, the real risk is not in changing direction, but rather in maintaining one's present course.

Exponential or near-exponential advances in everything from computer processing power to data storage to bandwidth, and amazing scientific advances in disease diagnostic technology, brain scanning technology, pharmacogenetics, and proteomics, are poised to usher in an age of unprecedented change -- change that will require many corporations to modify their existing business models or adopt new ones if they hope to remain competitive.

Foolish final word
Although Lewis and Clark made the correct decision in regards to the forked river, it is important to understand that their journey wasn't over. They still had to cross the Rockies and then navigate down the untamed Columbia River in order to reach the Pacific. Then, of course, they had to successfully make the return trip.

Like investing, it was a treacherous, nerve-racking trip at times; and at various points the Corps of Discovery suffered setbacks. But it is important to know that the team always kept moving forward. Or, in the words of Lewis and Clark, "We proceeded on."

Investors must likewise do the same. And by doing their due diligence, diversifying their portfolios, and taking timely strategic risks, investors should be able to safely navigate their investing expedition and reach retirement in a safe, comfortable and reasonably timely fashion.

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Fool contributor Jack Uldrich is the author of two books on nanotechnology, as well as Into the Unknown: Leadership Lessons from Lewis & Clark's Daring Westward Expedition. He owns stock in GE, but none of the other companies mentioned in this article. The Fool has a strictdisclosure policy.