If you want to see how Denver transformed itself from a high-plains cactus patch into the West's leading cowtown, grab a bicycle and head for the South Platte River trail. Start at Chatfield Dam, built after the devastating flood of 1965, which created a crucial water source for the metro area. Heading north toward downtown, you'll pass acres of suburban bluegrass lawns soaking up enough of that water to float a cruise ship. Make a pit stop at Colorado's Ocean Journey, where you can witness an even more extravagant use of water to support sharks, tigers and assorted other creatures that were never meant to live here. Finally, just over the Adams County line, you'll come to the Metro Wastewater treatment plan, where a frothy waterfall cascades into the river and the abuse of the South Platte reaches a smelly finale. Bottoms up!