Where Can You Swim and Do Watersports near Longmont? Best Longmont Lakes & Reservoirs

While the Front Range is hardly the land of ten thousand lakes, Longmont is surrounded by plenty of scenic lakes and reservoirs.

As the weather warms up, nearby lakes are great for:

• Swimming at sandy beaches
• Fishing for bass, trout, and catfish
• Paddleboarding and kayaking on calm, clear waters
• Boating and watersports like wakeboarding and windsurfing

A day at one of these Longmont lakes is one of the best ways to enjoy spring and summer in northern Colorado!

However, because many reservoirs are conserved habitats or used for managing our water supply, different locations have different rules for swimming and watersports.

What’s Allowed at Lakes & Reservoirs Near Longmont

Lake/Reservoir	Swim Area	Paddle Sports	Fishing	Boating	Trails
Union Reservoir	✅	✅	✅	✅	✅
McIntosh Lake	❌	✅	✅	❌	✅
Pella Crossing	❌	✅	✅	❌	✅
Lagerman Reservoir	❌	✅	✅	✅ (non-motorized)	✅
Gross Reservoir	❌	✅	✅	✅ (motorized)	✅
Golden Ponds	❌	❌	✅	❌	✅
McCall Lake	❌	❌	✅	❌	❌

What Lakes Can I Swim in Near Longmont?

If you’re looking to cool off near Longmont, Union Reservoir is the best public lake for swimming.

Located just east of town in Boulder County, this 736-acre reservoir is the only nearby lake or reservoir with a designated swim beach (swimming outside the beach area is not allowed). 

It’s open seasonally from Memorial Day until Labor Day and offers:

• A sandy shoreline for sunbathing
• Shallow entry points, great for kids and families
• Calm water ideal for floating or wading

While you’re there, you can also enjoy:

• Paddleboarding and kayaking from the boat launch
• Fishing for catfish, bass, and trout
• Grassy areas and picnic tables for a full-day outing

Other nearby lakes—like McIntosh or Lagerman—are perfect for paddling, but swimming is not permitted.

Best Paddleboarding & Kayaking Spots

McIntosh Lake

McIntosh Lake is one of the most popular spots for paddleboarding in Longmont. 

Its flatwater surface makes it perfect for beginners, and there’s a convenient launch area along the shoreline.

The city park offers:

• A scenic 3.5-mile loop trail for walking or jogging
• Views of Longs Peak and the Front Range
• Frequent sightings of herons, geese, and eagles

Lagerman Reservoir

Located southwest of town, Lagerman Reservoir is quiet and less busy than other lakes. Usually, the reservoir provides:

• Open water with minimal wake or wind chop
• Surrounding multi-use trails for hiking or cycling
• Excellent birdwatching opportunities year-round

However, the reservoir is not currently stocked with fish due to poor oxygen levels and the boat ramp is closed due to low water levels.

Pella Crossing

Just south of Hygiene, Pella Crossing is a county open space made up of several small ponds. This no-motor zone is:

• Great for slow, exploratory paddling
• Surrounded by open space and wildlife habitats
• A favorite for nature lovers and photographers

Fishing Lakes Around Longmont

Union Reservoir

Union Reservoir is one of the best spots for anglers in the area. The lake supports a variety of species, including:

• Wipers
• Largemouth bass
• Channel catfish

You can fish from the shoreline, launch a small boat, or even combine fishing with sailboating or paddleboarding.

McCall Lake

Located just east of Lyons, McCall Lake is a warm water fishery used for city irrigation.

Fish stocked in the lake include:

• Catfish
• Crappie
• Bluegill

McCall is a bit further than Union Reservoir or Golden Ponds, but still easily accessible and a touch more rustic.

Golden Ponds

This park features four ponds with multiple access points and wide shoreline areas.

Common catches include bass and sunfish.

It’s a great choice for a quiet day of casting close to town.

Loomiller Park/Izaak Walton Ponds

Designed for youth fishing, these ponds are great for families.

Both spots are stocked and managed to encourage beginner-friendly fishing experiences.

Pella Crossing

Located near Hygiene, Pella Crossing includes six small ponds and is known for its quiet, natural setting.

Expect to catch:

• Largemouth bass
• Bluegill
• Catfish

Fishing is limited to shoreline access, but the scenery and wildlife make it a favorite among local anglers.

Longmont Lakes for Boating & Watersports

Union Reservoir

Union Reservoir in Longmont is a top choice for recreational boating and wind-powered sports.

It allows both electric motor and non-motorized boats, making it a flexible option for a variety of watercraft.

Popular activities include:

• Windsurfing and sailing on windy days
• Kayaking and paddleboarding in calmer conditions
• Canoeing along the quiet northern shoreline

Boat rentals and launch facilities are available on-site, making it easy to get on the water even without your own gear.

Boulder Reservoir

Just a short drive south, Boulder Reservoir offers a broader range of boating and high-speed watersports.

This 700-acre lake allows:

• Motorized boats for cruising and waterskiing
• Designated ski-only days for safety and clear access
• SUP and kayak access in no-wake zones

Swimming is restricted to guarded swim areas only.

Permits are required for all watercraft, and boat inspections are enforced.

Gross Reservoir

Tucked into the foothills southwest of Boulder (about an hour drive from Longmont), Gross Reservoir is known for its mountain scenery and watersports.

Managed by Denver Water, the reservoir supports:

• Motorized boating 
• Kayaking 
• Canoeing
• Stand-up paddleboarding

The steep cliffs and expansive surface make it a favorite for thrill-seekers.

You’ll often see wakeboarders and waterskiers taking advantage of the open water.

Note: Swimming is prohibited due to water management policies.

FAQ

Can you swim at Union Reservoir?

Yes, it has a swim beach open in summer with a lifeguard present.

Where can I go wakeboarding near Longmont?

Boulder Reservoir is the closest option for watersports like wakeboarding. Gross Reservoir is a little further but also allows watersports.

Can you use a motorboat at any Longmont lakes?

Union and Gross Reservoirs allow motorized boating in designated areas.

Where can beginners try paddleboarding?

McIntosh Lake is the most beginner-friendly spot. Pella Crossing also offers a peaceful location to try paddleboarding.

Is fishing allowed at all these lakes?

Yes, most have active fisheries and allow fishing with a license. Lagerman Reservoir is the exception, as no fish are currently stocked due to poor oxygen levels.

Which lakes are best for nature walks?

McIntosh Lake, Pella Crossing, and Lagerman Preserve offer scenic trails.