The Lone Ranger rode a mighty steed, indeed. These days, a masked man on horseback with six-shooters on his hip is more likely to attract the scrutiny of Homeland Security than he is to attain hero status.

Fortunately, Fools have the option to ride a different sort of silver altogether, and Pan American Silver (Nasdaq: PAAS) is one of several silver thoroughbreds that I consider capable of carting investors to sizeable long-term gains.

Pan American galloped into earnings with a 67% surge in fourth-quarter profit to $46.4 million. Fools eager to gauge the impact of silver's dramatic late-2010 price gains upon the profitability of miners will note that Pan American scored more than 40% of its full-year profit during the quarter, even though fourth-quarter silver production accounted for just 23.5% of the 2010 total.

The miner delivered its fifteenth consecutive year of production growth with output of 24.3 million ounces, though the 1% to 5% decline anticipated for 2011 appears poised to interrupt that impressive streak. Citing a range of pressures from exchange rates to labor costs, Pan American revealed guidance for a 23% to 32% cost increase, to a range between $7 and $7.50 from the impressive mark of $5.69 achieved for 2010.

To assuage the concerns of cost-conscious Fools, I hasten to point out that at present silver prices above $30 per ounce, even at the high end of that cost estimate, Pan American could still enjoy an operating margin of 75% or more! In fact, I expect continued strength from silver in 2011 to defend those margins against contraction. It is worth noting, however, that China-focused Silvercorp Metals (NYSE: SVM) continues to impress with a negative production cost of ($5.93) per ounce of silver for its third quarter of fiscal 2011. After applying its lead and zinc sales to the silver cost structure, in other words, Silvercorp is essentially paid to pull silver out of the ground.

Looking further afield, we find Pan American's aspirations for nearly doubling the scale of its production profile trailing those of superstar Silver Wheaton (NYSE: SLW) by only one year's time. While Silver Wheaton's projected growth spurt rests on the heels of two slam-dunk projects -- the ongoing expansion of Goldcorp's (NYSE: GG) Penasquito output, and the subsequent completion of Barrick Gold's (NYSE: ABX) Pascua Lama mine -- Pan American carries its silver eggs in one somewhat less certain basket.

Although the company expresses confidence that Argentinean law will be amended to permit construction of the Navidad project, the fact that the region remains subject to a mining ban forces the market to discount the project substantially. On the other hand, with an enterprise value that's more than 70% smaller than that of Silver Wheaton, Pan American investors can look forward to a brisk revaluation of shares to follow any such political victory for Navidad.

While I do vastly prefer recent AMEX inductee Great Panther Silver (AMEX: GPL) and fellow growth engine Endeavour Silver (AMEX: EXK) for some of the highest-octane exposure to silver, Pan American remains a large-cap thoroughbred of undeniable quality and value. Add your favorite silver steeds to your Motley Fool watchlist by clicking on the links below, and track all the Foolish coverage of these silver bullets.