There are a number of linked system in Colorado.
Probably the oldest system that covers about 80% of the state as well as parts of Wyoming and New Mexico with over 20 analog 2-meter repeaters. It is not a club, but a 501(c)(3) and supported by donations.
The Colorado Connection also host the Colorado Emergency Reporting Network (CREN). CERN volunteers monitor the Colorado Connection 24/7 for any emergencies or requests for assistance where the caller is out of range of the cell network or otherwise can’t call 9-1-1.
The Colorado 4×4 Rescue and Recovery group use the repeater network when on recoveries in the Rocky Mountain and Colorado back country 4×4 trails.
The Rocky Mountain Ham Radio group is also a 501(c)(3) and provides a DMR network that covers Colorado and parts of Wyoming and New Mexico.
The system has a number of different ‘zones’ so you can select to bring up a northern, southern, central or other specific zones or the entire network. They have also recently added the capability to connect to some of the zones (but not the whole network) through a Brandmeister talk group and a Pi-Star hotspot.
The RMHAM group has also developed a Amateur Radio microwave network across three states.
From their web page: connections include radio sites from Cheyenne, Wyoming along the front range in Fort Collins, Longmont, Boulder, Denver, Colorado Springs, Vail, Grand Junction, Pueblo and Cañon City, west toward Salida, and south to San Antonio Mountain, New Mexico. New Mexico’s coverage is from Albuquerque to Santa Fe, to Taos to San Antonio Mountain.
The microwave carries connections for the DMR repeaters, Colorado Connection and other partners such as the Fun Machine.
They also provides sample codeplugs for many of the DMR radios. So if you are new you can download the appropriate codeplug for your radio, change the ID to your DMR ID and can be on the air.
The Fun Machine is a network of about 12 70-cm repeaters. Built to support emergency communications it provides links via AllStar mostly to counties in the southern part of the state such as Chaffee (Salida), El Paso, Fremont, Custer, Pueblo, Mineral, Las Animas. There are other repeaters in Douglas and Denver counties.
Regular nets include Colorado ARES Region 5 District 2 on Sunday and Colorado ARES. Region 5 District 1 (Fremont/Custer) on Monday.
This is a multi-state system of linked repeaters and nodes, covering Colorado, California, Nebraska and New Mexico.
There are regular nets on the system throughout the week including the Digital Learning Net on Wednesdays at 7pm local and the Denver Area Council Boy Scouts Amateur Radio Club net on the first and third Sundays of each month at 7:30pm Mountain time.
Other Linked Systems
Additional linked systems include
With analog, DMR, D-STAR and Fusion repeaters and host of the Colorado Mega Reflector.
PRA has repeaters on Squaw Mountain and in Elizabeth and Parker.
Mostly New Mexico and Texas but with a repeater in Canon City Colorado.
With repeaters on Badger Mountain, Fremont Peak, Colorado Springs and Pueblo.
With repeaters in western Colorado and eastern Utah.
There are also a couple of repeaters linked to the Cactus Intertie System which has repeaters in large portions of California, Arizona, New Mexico, Nevada, Utah, Colorado and Texas. Additional coverage is available in the Washington D.C. and the surrounding areas of Maryland, Virginia, West Virginia, Pennsylvania and Delaware on a full time basis. Additional coverage is also available on a full time basis in the Atlanta, Georgia and the Kalispell, Montana area [from their web site].