Maybe. What you need is a freeride bike, which is sort of a cross between a "cross-country" mountain bikean all-purpose bikeand a super-strong downhill bike. Freeride bikes tend to weigh a bit more than XC bikes, but have more suspension travel and usually a beefier frame. One good example: Marin's Rock Springs ($1,785; www.marinbikes.com). It's a very tough rig, with dual suspension, adjustable travel for both front and back, and Hayes disc brakes. Weight is not badabout 28 to 29 pounds for a bike that will fit you. It'll take you just about anywhere you want to go on a mountain. Another nice bike is the Giant AC 2 ($2,400; www.giant-bicycle.com). Similar in overall specs to the Rock Springsa very rugged bike with lots of travel and the ability to survive jumps and rocks with you riding it. Meanwhile, it has a nicer component set than the Marin (mostly Shimano XT), hence the higher price.
If those two are a bit rich for you, a bike such as K2's Lithium 3.0 should cut the mustard ($1,100; www.k2bike.com). A little lighter construction than the Marin or Giant, but should be tough enough. Really, all mountain-bike frames are seriously over-built. They do on occasion break, but that's under pretty extreme duress. Usually it's the components that bend firstthe wheels, shocks, and so on. That's where you may find you have to spend a little more scratch on maintenance and replacement than a rider who weighs 30 to 40 pounds less than you.
In any event, have fun!
Find reviews of this year's best mountain and road bikes in Outside's 2004 Buyer's Guide.