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Union Reservoir

Status:  Log in or Register... 10.29.21
Water Tmp:  10.29.21
Level:  10.29.21
  Conditions Report
Conditions reports for this lake are available when logged in. Last Conditions Report for Union Reservoir: 10.29.21
Union Reservoir on FishExplorer has 407 historic conditions reports, 287 historic water temperature updates, 179 historic status updates, 284 historic water level updates, available to subscribers.
Lake Skipper(s):
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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photo by The Dooze photo by kd0gmy photo by TADA32 photo by TADA32 photo by TADA32 photo by papabatman view more photos...
There are 20 photos on FishExplorer for Union Reservoir. Subscribe to FxR+ to see them all.
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, windsurfi... 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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Recent Related Content
Union res. 7-3 07.03.20 by Eyefishing
Shout out to J Shanko 05.27.20 by hunter creek
Crappie 09.02.18 by BioWyo
It finally happened... 08.12.18 by catman82
Greedy Union Res 06.26.17 by tub
Union Master Angler Awards
Aggregated Master Angler records are available for FxR+ subscribers.
There are 10 Master Angler records available on FishExplorer to view associated with Union Reservoir.
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Conditions History
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Union Reservoir Stocking 2018 to 2020
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Boat Ramps
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Lake Class: 1
Operation Game Thief
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