Missouri’s Katy Trail State Park is a cyclist’s dream. Created by repurposing a 237-mile-long stretch of the old Missouri-Kansas-Texas Railroad, the bicycle trail cuts across Missouri’s midriff with over half its length following Lewis & Clark’s path up the Missouri River as they launched their epic expedition of discovery.

The mostly flat throughway weaves through some of the Show Me State’s finest scenery — rolling farmland, forests, tallgrass prairies and towering limestone bluffs where eagles circle overhead. Many riders camp along the way while others choose to stay at one of a number of quaint B&Bs where owners are well-acquainted with the needs of touring cyclists.

Katy Trail is typical of a fast-growing number of long-distance cycling routes crisscrossing America that have inspired development of a national cycling route network known as the United States Bicycle Route System (USBRS).

The USBRS was established in 1978 by the American Association of State Highway and Transportation Officials (AASHTO), the same body that coordinates the numbering of interstate highways and U.S. routes. The stated purpose of the system is to facilitate travel over routes deemed most suitable for cycling — including multiple types of bicycling infrastructure, such as low-traffic roads, bike lanes and off-road trails.

In order for a route to qualify as a USBRS route, it must either connect two or more states, connect multiple USBRS routes, or connect a U.S. Bike Route with a national border.

The first routes were defined in 1982: USBR 1 from North Carolina to Virginia, and USBR 76 from Illinois through Kentucky to Virginia. Development of the system lagged as administration shifted from AASHTO to the Federal Highway Administration (FHWA) in 2009 — leaving these two as the only routes in the system until 2011.

Under new direction and with significant support from the Adventure Cycling Association and various state highway departments, major expansion of the system began in 2011 with the addition of eight more routes.

Meanwhile, America’s interest in cycling has skyrocketed — shifting from an insider club of Lycra-clad enthusiasts to a far more diverse demographic. The number of cyclists in the U.S. has increased over the past three years from around 43 million to nearly 50 million, and bikes have outsold cars in most years since 2003. The USBRS has benefitted from the boom and the system presently boasts routes totaling more than 14,000 miles across 27 states and Washington DC.

Once fully connected, the USBRS is projected to encompass more than 50,000 miles of bike routes. Here are a few other popular USBRS routes:

South Lake Tahoe to Baker, Nevada (Bike Route 50). Nevada’s first U.S. Bike Route is a monster ride, traversing 410 miles of the Great Basin on a stretch of Highway 50 known as the Loneliest Road in America. The route offers just about every environment imaginable, ranging from desert salt flats and sagebrush fields to a dozen summits that top 6,000 feet. There’s some history here as well — Bike Route 50 parallels the 19th century route of the Pony Express.

Mitchellville, Tennessee to Hodgenville, Kentucky (Bike Route 23). Riders share backcountry two-lane roads with Amish buggies on this new 109-mile route that connects with an existing USBRS segment in Tennessee. Gentle hills, fertile farmland and friendly towns greet riders who can take a break to visit a Civil War battlefield in Munfordville, Kentucky, and Mammoth Cave National Park, home to the world’s largest cave system.

Baxter Springs, Kansas to St. Louis, Missouri (Bike Route 66). An historic pilgrimage for motorized road-trippers, fabled Route 66 now draws cyclists who can absorb the nostalgia at a slower pace. The 358-mile route through southeast Kansas and Missouri is the first section of the “Mother Road” to be designated for bikes. The route is packed with quirky attractions including 1950s gas stations, souvenir shops and tourist courts. When 66 gets busy, the route smartly deviates onto quiet back roads.

To explore all USBRS routes and download free digital maps, go to www.adventurecycling.org.