If I Were Going...: Rocky Mountain National Park in Fall and Winter

Rocky Mountain Bull Elk

I recently posted a blog about "Moosecapade" in 2020 in which I discussed Rocky Mountain National Park (RMNP) at length.

RMNP hike, 1975

I can't talk only about my summertime visits, however.

I need to give some love to RMNP in the fall and winter, both beautiful times to visit.

It was early fall the first time Scott and I visited RMNP back in 1975 when we took an extended trip out west, the year after we were married.

That's when I decided I wanted to live in Colorado. It only took 34 years!

Fall moving toward winter in RMNP

Elk Rut

In addition to visiting RMNP at least once -- and usually multiple times -- every summer, we also go almost every fall for the Elk rut. Think of it as going to watch an episode of Planet Earth or Wild Kingdom in person.

Bugling bull

Late August through October is mating season for Rocky Mountain Elk in RMNP, with October being the most exciting time to visit.

Called the "rut," it's a complex process that can be literally life or death for bull Elk. It is a graphic display of male primal urge to perpetuate blood lines by beating out competing males in order to sire multiple offspring.

Fall antlers ready to defend the harem

The most important aspect of the rut is bulls gathering cows (and any calves that are still with their mothers) into small groups called harems.

Keeping his harem close

A lone bull

As the bulls gather their harems, they drive off any adolescent males that may still be with the cows, forcing them to retreat and gather with other young males into bachelor herds. Sometimes these juveniles still hang around the harems, confused about where they are supposed to go and invoking the ire of the bulls.

The bulls then protect and defend the remaining members of their harems until the cows are ready to mate. The defense includes fending off other bulls that are attempting to form their own harems. That's what those huge antlers are for.

Antlers can weigh 20 lbs. each, requiring strong neck muscles to support them

To attract a harem, bulls wallow in mud and urine to "perfume" themselves to attract cows. The mud has several purposes: it cools down the bull which often becomes overheated during the rut, it more evenly spreads the urine scent over his body and makes the bull look more threatening to other bulls.

This bull is damp from wallowing

In August, the antlers are still coated in "velvet," a fuzzy blood-rich coating that feeds the growing antlers.

Elk in velvet

By September, the antlers have reached their full glory and the velvet dies back and sloughs off. Bulls remove the tattered velvet and polish their antlers by rubbing trees, shrubs and the ground, often ripping up clumps of grass or branches.

Digging up grass with his antlers

The vigorous rubbing also releases pent-up energy and leaves behind scent to mark territory. This virile display, combined with loud bugling and whistling, piques the interest of the cows and intimidates competing males.

A bull guards his harem

Because older, larger bulls bugle more loudly than their young rivals, the cow listens to the call to decide if she wants to stay with her current harem or bolt to join another bull. Bulls also bugle to announce or accept a challenge from another male.

Keeping a wayward female in line

In the process of guarding their harems from other bulls -- or of trying to lure cows from other harems -- bulls sometimes fight violently with other bulls. But, these battles often include more posturing and posing than actual fighting. A young male will probably retreat rather than engage in a fruitless battle with a mature bull.

Pre-fight "dance"

Before a fight begins, bulls equal in size typically assess each other's antlers and bodies to determine their chances of winning. They display their dominance by bugling and thrashing the ground with their antlers.

An actual fight involves locked antlers

They often stare each other down for long periods. Or, they walk side by side, turning suddenly before either engaging in a fight or retreating to continue their assessment. If they do decide to fight, they lower their heads, lock antlers and shove each other in earnest.

Elk fight

Fighting is intended to be a show of strength, with the winner maintaining (or stealing) the harem and the loser retreating. While seldom a battle to death, bulls do get hurt. The most common injuries are broken antlers or puncture wounds from the rival's antlers. See (and hear) a fight here.

Young males sparring -- and not impressing this female

A bull interacts with cows in his harem in two ways: herding and courtship. When a female wanders too far away from the harem's range, the male will rush ahead of her, block her path and aggressively push her back to the harem. Herding behavior is accompanied by a stretched out and lowered neck with the antlers laid back. Sometimes a bull even hits the cow with his antlers.

A vocal bull Elk

When the cows come into estrus ("heat"), mating begins. A bull elk must be ready because a cow is receptive for mating for less than one day per cycle and she won't be willing to mate again until her next estrus arrives in 20 days. Cows can have up to four estrus cycles each season, but most cows become pregnant during the first or second cycle.

Cow nursing this year's calf

Signaling a female

During courtship, the bull approaches the female with his head and antlers raised.

The male signals his intention to test the female for sexual receptivity by flicking his tongue. If not ready, a cow will lower her head and weave from side to side while opening and closing her mouth.

The bull will stop in response in order not to scare her. Otherwise, the bull will lick the female and mate. You can often see bulls sniffing the air -- or the cows -- to determine if the cows have come into heat.

Courtship

Each day, the action generally begins in the late afternoon. During the day, the Elk are often resting in the forest. As sunset approaches, they move into open fields and begin their displays. People bring lawn chairs and binoculars or cameras on tripods and settle in for the show. RMNP restricts access the fields, requiring watchers to stay close to the road and move out of the way if Elk approach. Rangers patrol the area to make sure people stay safe.

Bulls can be very aggressive when defending their harems

Although Elk are not predators, they are quite dangerous any time of year because of their size; bulls weigh 400-1,000 lbs. and females 350-450 lbs. During the rut, bulls are especially dangerous because of their sharp antlers and their testosterone-fueled aggressiveness. Bulls are very territorial and defend their harems from any threat, including people and vehicles.

The iconic fall Elk

Rocky Mountain Elk were reintroduced in 1913 to Colorado from Wyoming after near extinction of the regional herds. While overhunting was a significant contributing factor, the Elk's demise was mainly attributed to human encroachment and destruction of their natural habitats and migratory corridors.

These magnificent animals were almost gone

Now, Elk are the most abundant wild animals in RMNP. As many as 3,200 are scattered throughout the Park during the summer and fall, with 600-800 wintering there.

In fall you see large harems, but not as large as spring herds of cows with calves

Bulls shed their antlers between January and April, with the majority losing their racks in March. And, then, they begin growing next year's antlers.

Spring Elk

Other Animals

Of course Elk are not the only animals you can see in the fall. They are just the most popular. The town of Estes Park even has an Elkfest each October.

But, what else have I seen in the fall? And, you may ask, what about the Moose rut?

Moose mate around the same time as the Elk, but they tend to disappear into the mountains rather than conducting a major display.

Moose are more solitary than Elk and, therefore, do not form large harems. I have seen Moose rutting in Alaska, but never in RMNP.

Fall Moose in Grand Lake

But then, I rarely go to the West Side of RMNP, where most of the Moose in the Park live, after Trail Ridge Road closes in the late fall. When I have gone, I have seen some pretty spectacular bulls, including some that were losing their velvet. But, that was a prelude to their rut.

Two bulls losing their velvet

Plus, I have seen a Bear (just one fall Bear in all those visits) ...

A rare sight in RMNP

Mule Deer ...

Another animal that grows and loses antlers each year

Bighorn Sheep ...

RMNP's "mascot" animal, although not the most common

Least Chipmunks ...

Cute little guy

Mountain Bluebirds ...

A male and female in the bush and a female on the branch

Steller's Jays ...

One of Colorado's prettiest birds

Dusky Grouse ...

This one was hanging out in Endo Valley

Wilson's Warblers ...

An immature Wilson's Warbler (hence no "black beret")

And, big old Tom Turkeys ...

Gobble, gobble

Fall Foliage

Of course, the Elk rut is not the only reason to visit RMNP in the fall. The crowds are much smaller (except at the height of the rut) and the fall foliage is beautiful.

Fall hillside

Now, RMNP's color is mainly from Aspens which turn predominantly yellow, mixed in with various shades of orange. This is not the blazing bright reds of a New England fall.

Aspen leaf

But, it is still pretty.

Aspens are predominantly yellow in fall, but some turn orange

Aspens are opportunistic and grow much faster than evergreen trees, so, wherever there has been a fire or beetle kill or other destruction of evergreens, you can see the emergence of Aspens.

You can see where evergreens have been felled

And this is most prominent in the fall.

Trees near the Grand Lake entrance

The colors peak in late September/early October, but timing it is dicey.

Trees ablaze

The higher the elevation, the earlier the trees change and then lose their leaves. Plus, sudden storms can strip the trees of leaves, changing the landscape from autumn to winter overnight.

Fall reflection

Winter

And, let's not forget winter. When the roads are clear, it's a great time to visit RMNP to see the ground shrouded in snow.

A typical sunny winter day in RMNP

It can be cold and windy. But, probably not as bad as you think. Average winter temperatures are around 40°F in the daytime and 18°F at night.

The wind creates a wave over the mountains

And gorgeous.

RMNP from Estes Park

Access is more limited (Trail Ridge Road closes in October and doesn't reopen until late May or early June) and road clearing can be hit-or-miss, so you have to be cognizant of weather forecasts.

Winter Aspens

Someday, I swear, I will actually go snow-shoeing there.

An Elk in the snow

Raptors

Another cold-weather treat that Caty and I have participated in non-pandemic years is Owl banding in RMNP. The Colorado Avian Research and Rehabilitation Institute (CARRI) bands both Boreal and Saw-whet Owls at the Hidden Valley area of RMNP during October.

Boreal Owl being banded

I have attended several times and seen a couple of Boreal Owls, but never a Saw-whet, despite Saw-whets being allegedly more common. These diminutive critters are nocturnal, so the banding sessions go late into the evening. But, they present an opportunity to see an Owl you might never find on your own.

Recently banded Boreal Owl at RMNP

Winter into early spring is when Great Horned Owls nest in and near RMNP.

Daddy Owl guarding the nest, 2018

There is a pair of Great Horned Owls that nest every year behind the parking lot of the public library in Estes Park.

Adorable Great Horned Owlets, 2016

Some years they nest in a cleft in the rocks ...

Cleft nest, 2014

... and some years on a ledge smack in the middle of the cliff ...

Ledge nest, 2016

I can't tell you how many hours I have spent watching multiple broods as the babies mature and learn to use their wings.

Stretching those wings

And, I can't tell you how many times people approached us to see what we were doing and could not find the well-camouflaged Owls without lots of assistance.

Very difficult to see despite being very close

In the past, there was a pair that nested just past the Fall River Entrance, but they moved elsewhere several years ago.

This nest in now abandoned; photo 2015

Parts of the Park are closed off every year to protect nesting Peregrine Falcons, but the nest is virtually impossible to see, even with a scope. Peregrines were reintroduced into the Park years ago, but there are very few sightings. Allegedly the Park is also home to Golden Eagles, but I have never seen any there. I have seen Bald Eagles and Ospreys in Estes Park and Grand Lake and Kestrels and Red-tailed Hawks in the Park.