Each state has its own laws and regulations regarding the scattering and burying of cremated remains. In Colorado, you can scatter or bury on your own private land, or on someone else’s, with permission from the landowner. Officially, you should seek permission to scatter or bury on federal land. However, as with local and state land, it is unlikely you will meet with opposition if you are discrete and away from main thoroughfares and waterways. Some national parks have applications for conducting the scattering of ashes. Here is a link to information about Rocky Mountain National Park and scattering.