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Union Reservoir

Status:  Log in or Register... 09.16.20
Water Tmp:  09.16.20
Level:  09.16.20
  Conditions Report
Conditions reports for this lake are available when logged in. Last Conditions Report for Union Reservoir: 09.16.20
jshankoRegional Editor:
Jon Shanko
Fish Species in Union Reservoir:
Black Bullhead, Black Crappie, Bluegill, (Log in for full fish species list)
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Union Reservoir
Managing Agency: Surface Acres: Capacity AF: Elev:
City of Longmont Log in to view full details on lakes and rivers on
Originally called Calkins Lake, the Union Reservoir was carved out during the last glacial age and is one of only a few natural lakes in Colorado. In 1903, the Union Ditch Company began drilling a tunnel to release water into the St Vrain River. According to Colorado water law, that made Union a true reservoir. Today, visitors to Union Reservoir enjoy fishing, swimming, wakeless boating, camping, ... Log in for additional details...

Getting there:

Take I-25 to Highway 119 (Longmont exit). Go west to County Line Road 1. Go north approximately 3/4 of a mile and turn right at the sign for Union Reservoir. The entrance is about 1/2 mile up this road on your left.

Additional Lake Information for Union Reservoir:

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Conditions History
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Union Reservoir Stocking 2017 to 2019
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Boat Ramps
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Lake Class: 1