All snowmobiles operated on public land must be registered and display a current registration sticker from Colorado Parks and Wildlife. Similar to ATV registration, Colorado residents must register their snowmobile but nonresidents are not required to register. However nonresidents must purchase a permit to ride in the state of Colorado. Permits can be purchased via mail or online. For residents needing to register their snowmobile, your snowmobile can be registered at a Colorado Parks and Wildlife office or snowmobile dealers. Please bring proof of ownership.
Check out these Littleton, CO ATV/OHV resources: