Calkins Lake

Calkins Lake sits within the Union Reservoir recreation area near Longmont in Weld County, offering one of the Front Range's most accessible spots for paddleboarding, swimming, and warm-weather water sports. The reservoir draws families, dog owners, and anglers from across the Denver metro area, and visitors consistently praise the sandy beach, shallow entry waters, and on-site watercraft rentals that make a day on the water easy to plan.

Paddleboarding ranks as the top activity at Calkins Lake, with rental options available on-site alongside kayaks. Staff provide fitting for life jackets and brief instructional lessons before launching, making the experience beginner-friendly. The reservoir's size allows comfortable room for paddle boarding sessions, and portable speakers are permitted on the water. Kayaking draws a similar crowd, with well-maintained rental boats and calm surface conditions on most mornings before afternoon winds pick up.

The designated swimming beach features soft sand, shallow water ideal for young children, and a nearby playground. A separate dog beach allows pets to swim and interact off-leash, though human swimming is restricted to wading in that section. Families report spending full afternoons rotating between the beach, playground, and water without running out of things to do. An ice cream truck sometimes parks near the beach area during peak season.

Fishing at Calkins Lake produces multiple species, with wiper being the standout catch. Anglers report landing wiper up to seventeen pounds, particularly on fly tackle, and describe them as the hardest-fighting freshwater fish in Colorado. Longtime visitors consider this reservoir a top wiper fishery and recommend arriving early on weekends to secure a prime shoreline spot.

Facilities include portable restrooms, parking, and shade trees spread across the picnic areas. Entry requires a separate fee from Colorado State Parks passes, with parking costing around ten dollars. The reservoir has hosted triathlons and open water swim events, confirming its suitability for competitive swimming distances.

The biggest frustration visitors report is the entry line. Weekend waits of one to three hours are common, especially after mid-morning, as the parking lot fills and a one-in-one-out system takes effect. Arriving before nine on weekends or visiting on late weekday afternoons dramatically cuts wait times. Late afternoon arrivals around five-thirty report walking straight in with easy parking. No motorized watercraft are allowed on the reservoir, keeping the water calm for paddlers and swimmers. Alcohol is prohibited, and rangers actively enforce safety rules including mandatory life jackets and whistles on all watercraft. Water quality can decline in late summer, occasionally prompting swimming advisories, so checking conditions before a visit is smart planning during August and September.