Is swimming allowed at Thunder Falls?

No, swimming is not allowed at Thunder Falls.

Nearby gauge (Grand Lake Outlet) · -50 ft³/s · About average

Thunder Falls

Q: Are dogs allowed at Thunder Falls?

No, dogs are not allowed at Thunder Falls. Pets aren't allowed on any trail, tundra or meadow in Rocky Mountain National Park; leashed pets may stay on roads, parking areas, campgrounds and picnic areas.

Colorado • Rocky Mountain National Park

By Armen Suny · Last verified Oct 2026

LiDAR & 3D terrain

Also For 2 other waterfalls also named Thunder Falls, see below

Rocky Mountain National Park NP · National Park Service

Before you go

No maintained trail reaches Thunder Falls; you must leave the Lion Lake Trail and travel off-trail, about 14 miles round trip from the Wild Basin trailhead.

Photo Credits (5)

Zane Selvans CC BY-NC-SA 2.0 · Flickr

Christian Collins CC BY-SA 2.0 · Flickr

Scrubhiker (USCdyer) CC BY-NC 2.0 · Flickr

Grand Canyon NPS CC BY 2.0 · Flickr

Jesse Varner CC BY-NC-SA 2.0 · Flickr

Difficulty

Hard

Trail Length

14.0 miles

Trail Type

Out And Back

About Thunder Falls

Thunder Falls is a long cascade in the Wild Basin area of Rocky Mountain National Park, on the slope just below Lion Lake No. 1. No trail reaches it: you can hear it from the Lion Lake Trail but cannot see it, and reaching it means leaving the trail and bushwhacking toward the sound of the water. Plan on a full-day backcountry trip of about 14 miles round trip from the Wild Basin trailhead.

The Setting

Thunder Falls sits at 10,892 feet within Rocky Mountain National Park, in the high alpine of Colorado.

Trail & Hike Details

Trail Description

From the Wild Basin trailhead, follow the Wild Basin Trail and Thunder Lake Trail, then branch onto the Lion Lake Trail. Just short of Lion Lake No. 1, leave the trail and travel off-trail to the falls. The NPS lists Lion Lake No. 1 at 7.0 miles one way with about 2,565 feet of gain, so the round trip to the falls is roughly 14 miles with well over 2,000 feet of climbing.

What to Expect

Expect a long climb through subalpine forest followed by steep, trailless terrain near the falls. The falls cannot be seen from any maintained trail, so only off-trail hikers will get a view.

Accessibility

The trail involves steep, uneven terrain with significant elevation change and is not accessible to mobility devices.

Frequently Asked Questions

🐶 Are Dogs Allowed at Thunder Falls?

❌ Dogs are not allowed
Pets aren't allowed on any trail, tundra or meadow in Rocky Mountain National Park; leashed pets may stay on roads, parking areas, campgrounds and picnic areas.

Are There Any Fees or Permits Required?

🤑 Fees are required

🏊 Is There Swimming at Thunder Falls?

❌ Swimming is not allowed

When to Visit

spring summer fall

Mid-summer to early fall, once snow has melted from the upper Lion Lake area; flow is highest in early summer during snowmelt.

Seasonal Access

The best time to visit is Spring, Summer, and Fall. Access roads and trails may close during winter due to snow. Check with Rocky Mountain National Park for current conditions.

Safety Information

The off-trail section is steep and rough, with wet rock near the water. Afternoon thunderstorms are common in summer, and cell service is unreliable in Wild Basin.

Current Water Conditions

Updated about 2 hours ago Barely Flowing

These readings come from the USGS gauge on Grand Lake Outlet, 10.1 miles away, not on Thunder Falls's own stream. Use them as a sign of whether the area is running wet or dry.

-50 ft³/s

Current discharge — how much water is flowing

About average for this time of year

Very Low Low Normal High Very High

Based on 5 years of record

8.50 ft

Water depth at gauge

7-Day Discharge Trend

What does this mean for your visit?

Flow is about average for this time of year.

About This Gauge

This gauge is on a nearby waterway and may not reflect exact conditions at the falls.

GRAND LAKE OUTLET BLW CHIPMUNK LN AT GRAND LK, CO

USGS 09014050

10.1 miles from waterfall

Drainage: 76 sq mi

Altitude: 8,365 ft

7-Day Flow Outlook

Based on the USGS gauge GRAND LAKE OUTLET BLW CHIPMUNK LN AT GRAND LK, CO (16 km away).

Moderate confidence

Barely Flowing right now

1 cfs

↓ Falling

Today

Barely Flowing

1 cfs

5/10

Tomorrow

Barely Flowing

1 cfs

5/10

Fri

Barely Flowing

0 cfs

5/10

Sat

Barely Flowing

0 cfs

3/10

Sun

Low

0 cfs

4/10

Mon

Barely Flowing

0 cfs

5/10

Tue

Barely Flowing

0 cfs

3/10

Best window: Today — barely flowing flow, sunny (trip score 5/10).

Best time of year: this gauge typically runs highest from early June to mid June, peaking in June.

How we calculate this

This is a transparent outlook, not a precise forecast. We take the waterfall's current flow strength (how it ranks against its historical normal for today, from the nearest USGS stream gauge), carry that ranking forward along the gauge's seasonal curve, and nudge it for forecast rain. Confidence is highest for the next day or two and falls further out. Always check official conditions and your own judgment before visiting — high flows can be dangerous.

Know when to go.

Get a free email alert when waterfalls near Allenspark hit peak flow. We only send when conditions are worth the trip — no weekly newsletters, no spam.

Is Thunder Falls Frozen?

Updated about 4 hours ago

Not frozen highs above freezing lately

Thunder Falls is not frozen right now; highs have been above freezing. Yesterday ran 38°F to 24°F.

Days below freezing: 2 of the last 14
Current cold streak: 0 days
Freezing days ahead: 0 of the next 7
Flow: 1 ft³/s

Winter safety. Frozen falls are the one waterfall trip with a documented injury pattern: falling ice, and ice-glazed rock and trail. Wear microspikes, keep well back from the base and from overhangs, and never walk out on ice over moving water.

Estimate from Open-Meteo daily temperatures at the falls, the LiDAR-measured facing direction, and the nearest stream gauge. It is a likelihood, not a report from the trail. See every frozen waterfall in Colorado.

Weather Forecast

The Terrain, Seen by LiDAR

Aircraft-mounted lasers measured this ground to within inches. Trees and buildings are digitally stripped away, leaving the bare shape of the land the water has carved.

Through the falls the surface drops roughly 199 feet over a short, steep run of tiers. Elevation at the pin is about 10,858 feet.

Steep ground runs through the entire stretch: about 163 feet of descent in the 500 feet above the pin and 118 feet in the 500 feet below it. Facing southwest, the falls sit in full sun for most of the day, best photographed early or late.

Aerial photo of the same ground around Thunder Falls near Allenspark, Colorado, for comparison with the lidar view

LiDAR bare-earth terrain around Thunder Falls near Allenspark, Colorado, showing about 199 feet of drop, a steep tiered drop, facing southwest

Aerial LiDAR bare earth

Drag to compare. The dot marks the waterfall. The frame is about a mile across.

Ground elevation: 10,858 feet; Measured by 1-meter lidar
Drop at the falls: About 199 feet; Change in ground height within ~250 feet of the falls
Faces: Southwest; Sunlit most of the day. Go early or late for softer light.

Ground profile through the falls

A slice through the lidar ground surface, from above the falls to downstream (heading southwest).

Elevation data: USGS 3D Elevation Program. Aerial imagery: USGS The National Map. Public domain.

Location & Access

Getting There

Thunder Falls is in the Wild Basin section of Rocky Mountain National Park, reached from the Wild Basin trailhead near the Wild Basin Ranger Station off Colorado Highway 7 near Allenspark. It is not near Glenwood Springs.

Get Directions on Google Maps

Parking

Park at the Wild Basin trailhead lot by the Wild Basin Ranger Station; spaces are limited, so arrive early in summer.

Elevation

10,892 feet above sea level

Coordinates

40.227485° N, -105.639726° W

Land Management

Rocky Mountain National Park NP

Managed by NPS

Visitor Tips & Gear

Carry a map and compass or GPS and know how to navigate off-trail. Start early to finish the long day and to get below treeline before afternoon thunderstorms. Bring plenty of water.

This trail sits at 10,892 ft — roughly 30% less oxygen than sea level

Extreme Altitude

At this elevation, altitude sickness is a real concern. Monitor how you feel, take frequent rest breaks, and descend if symptoms worsen. Visitors arriving from lower elevations should allow time to acclimatize.

As an Amazon Associate, we earn from qualifying purchases.

Coppertone Sport SPF 50 Sunscreen

UV intensity jumps ~4% per 1,000 ft — at this elevation you can burn in half the time.

Sun Bum SPF 30 Lip Balm (3-Pack)

Lips have almost no natural UV protection and burn fast in thin, dry mountain air.

Liquid I.V. Electrolyte Packets

You lose moisture ~2x faster at elevation — electrolytes help you absorb water efficiently.

ROCKNIGHT Polarized UV400 Sunglasses

High-altitude glare off rock and water is intense — UV400 lenses block 99%+ of UVA/UVB.

Boost Oxygen 10L Canister (2-Pack)

Portable supplemental oxygen for quick relief from headaches and shortness of breath.

Altitude Rx OxyBoost Complex

Antioxidant formula designed to support your body's natural altitude acclimation.

Fingertip Pulse Oximeter

Monitor blood oxygen in real time — SpO2 commonly drops to 85–90% above 10,000 ft.

Where to Stay

Browse vacation cabins and private rentals nearby

Glamping Hipcamp

Unique outdoor stays — tents, yurts, and treehouses

RV Rentals Outdoorsy

Rent a campervan or RV for your waterfall road trip

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Nearby Campground

CAMP DICK

9.3 miles away · 42 sites

Reservable

Overview Camp Dick is the site of a Civilian Conservation Corps camp that was established in the 1930s. It is located just off the Peak to Peak Scenic Byway, on the Middle Saint Vrain Creek.Recreation The Middle Saint Vrain Creek is a good fly-fishing stream where anglers cast for rainbow, brown and cutthroat trout. Many trails in the vicinity are open to hiking and biking, including Sourdough and Buchanan Pass trails. The Indian Peaks Wilderness boundary is four miles from the west end of the ca

Book on Recreation.gov