#58 - SNOTEL sites save many trips to high, cold places.

Map courtesy of Natural Resources and Conservation Service

The dots on this map mark the locations of automated stations that measure how much snow has fallen. The system, called SNOTEL (for SNOwpack TELemetry) is operated by the Natural Resource and Conservation Service. SNOTEL instruments help scientists to know how much snow sits in these remote mountainous locations, so that they don't have to visit the areas to make measurements.

Interactive SNOTEL Map of Montana

Right: I took this photo of my friend Mark at a SNOTEL site near Lincoln, Montana.

Important predictions . . .
The data obtained from the sites helps determine how much spring runoff to expect as the snow begins to melt. This is especially important in the management of reservoirs along Montana's rivers. For instance in April of 1996 Canyon Ferry Reservoir was lowered by over 15 feet because SNOTEL data indicated that there were unusually high amounts of snow present in the Upper Missouri Basin. Water from the reservoir was let through the dam in order to make room for the runoff that would certainly drain into Canyon Ferry as the snow began to melt rapidly in May and June.

A pillow sensitive to pressure . . .
Although SNOTEL sites have several types of weather instruments, the most interesting is the "snow pillow" (see picture below). The pillow is made of various materials including steel, rubber, and a material called hypalon. It is filled with a solution of antifreeze (50/50 mix of water and ethanol). As snow accumulates on the pillow, it increases the pressure within the pillow. A fluid line runs from the pillow to the shelter where an electronic device determines and records the snow's water equivalent. Periodically radio waves transmit this and other data to climatologists.

Unique to the West . . .
The SNOTEL system is the biggest provider of real-time snowpack and high elevation climatic data in the world. It is only used in the western part of the U.S.A. where there are about 650 sites - Montana has 90.

Terms: telemetry, reservoir

#60 - The Famous Egg Mountain Fossil Site near Choteau, Montana

Diagram courtesy of Montana Geologic Road sign program. A revolutionary discovery . . .
There have been some extraordinary dinosaur discoveries in our state over the past several decades, but the discovery that put Montana on the dinosaur map were found near Choteau in 1977 by Marion Brandvold, owner of the Trex Agate Shop (aka "The Rock Shop") in Bynum, Montana. The following year she showed the bones to paleontologist Jack Horner, and the rest is history. Horner and the late Bob Makela dug up the first nest of baby dinosaurs ever found. Over the next several years Horner and his team team discovered was 14 dinosaur nests in a single area of the site, providing the first strong proof that dinosaurs fed and cared for their young and exhibited complex social behaviors.

Good mothers . . .
The size of the shells indicated that the babies were about 12 inches long at birth, but bones of much larger infants were also discovered in some of the nests. This suggests that these dinosaurs cared for their young, unlike modern sea turtles that lay their eggs in the sand and leave the babies to fend for themselves. Furthermore, the teeth of the infants showed signs of wear, suggesting that the adults brought food to the nests. As a result, the newly discovered species (a type of duckbilled dinosaur) was named Maiasaura peeblesorum - Maiasaura is Greek for "good mother lizard", and Peebles honors the families of John and James Peebles, on whose land the finds were made.

Social colonies, nesting grounds . . .
Many of the nests were found at two locations called "Egg Mountain" and "Egg Island". These were small islands when the eggs were laid, yet the dinosaurs kept their nests separated by 23 feet, the approximate length of an adult Maiasaur. This suggests a type of cooperation typical of animals that live in groups. Nests at these two sites were found at three different levels, separated by layers of sandstone. Apparently the islands were nesting grounds that the Maiasaurs returned to year after year.

Term: paleontology

For a more detailed article about Egg Mountain, CLICK HERE.

Below: Illustration of a herd of Maiasaura walking along a creekbed, as found in the semi-arid Two Medicine Formation fossil bed. This region was characterized by volcanic ash layers and conifer, fern and horsetail vegetation. (Wikipedia)

#61 - Montana's Chinook Zone

Above: The area outlined in white is where Chinook winds are most common in Montana.

Strange winter warmth . . .
In Great Falls on January 11, 1980 the temperature rose from -32 F to 15 F in 15 minutes. During the night of January 14-15, 1972 an official weather observer in Loma (shown on map above) recorded a 103 degree change within 24 hours! The mercury went from -54 F to 49 F as calm arctic air was replaced by winds from the west blowing 30-40 mph. In both cases the dramatic warming was due to a weather phenomenon known as a Chinook Wind.

These unusually warm, winter winds happen at mid-latitude locations throughout the world and they are known by other names. In the west and northwest USA they are called Chinooks, and they can happen at any location that has high mountains to the west, such as the Helena Valley (15 miles east of the Continental Divide). They are most common along the eastern slopes of the Rockies from northern New Mexico all the way up through Alberta (Canada). The area of Montana outlined by the white line (see map above) is one place where Chinooks are especially common, and sometimes extreme.

Recipe for a Chinook . . .
In order for these warm winds to happen, three things are needed:

1. For one, a strong westerly (or southwesterly) flow of air is needed. West to east is the prevailing wind direction in Montana. However, if there is going to be a dramatic Chinook effect, the winds need to be especially strong.

2. Moist air from the Pacific is another key ingredient. This air contains an abundance of water vapor (humidity) that entered the air as water evaporated from the ocean. In order to make the change from liquid to vapor these water molecules had to absorb heat from their surroundings. So, especially moist air also contains lots of energy, referred to as "latent heat".

3. The final ingredient is mountains. Since the Rockies are somewhat narrower and higher in the area of Glacier Park and the Bob Marshall Wilderness, Chinook winds are especially frequent in the zone shown within the yellow line on the map.

Cloud formation releases the latent heat . . .
As the moist Pacific air blows into the mountains of Glacier Park, the mountains force the air to rise, causing the air to cool by expansion. As a result the vapor changes into ice crystals that grow and then fall as snow on the west slopes of the mountains. The key to the Chinook effect is that when the molecules of water vapor freeze, they release heat to their surroundings. This is the same latent heat that was absorbed as the molecules evaporated from the ocean. It is this heat that is released as clouds form on the west slopes that makes the Chinook winds so warm. As this air flows down the east side of the park into Browning, it will also be warmed by compression . . . But this warming by compression happens whether or not there is a Chinook wind. To view a short video about latent heat, CLICK HERE.

Below: The top diagram illustrates a situation in which air that is completely dry moves into Montana. Although air without even a trace of vapor is not realistic, the diagram shows the temperature changes associated with rising (expanding) and sinking (compressing) air. The bottom diagram shows the role that moisture-laden air plays in the development of Chinooks. With the heat released by water molecules as they become ice crystals, the temperature of the air as it reaches the peak is not nearly as cold. Then the air is compressed as it flows down slope toward Browning, reaching Chinook-like temperatures. NOTE: The diagram is highly simplified. The mountains between Washington and Montana are much more complex and the elevation of Browning is actually quite a bit higher than that of locations in Central Washington.

Term: latent heat

#62 - Canyon Ferry Dam on the Missouri River

This photo shows Canyon Ferry Dam and Reservoir, 13 miles northeast of Helena. The dam was built by the Bureau of Reclamation on the Missouri River between 1949 and 1954 . Like other dams in Montana, Canyon Ferry serves several purposes, including power generation, flood control, recreation, and irrigation.

Your dam wind . . .
One interesting aspect of the dam is a daily wind situation that exists here in the summer. According to a colleague of mine who used to do a lot of wind surfing, a significant wind develops by the middle of sunny summer days in the area between the dam and Cemetery Island. The wind, which blows from the dam to the island, is most likely caused by the fact that land heats up faster than water. As the morning sun shines on the area, the island warms up faster than the surrounding water. By mid-day this hotter air above the island begins to rise. This convection causes an area of low pressure to form over the island. A fairly strong wind begins to blow from the dam as cooler air from below the dam moves to replace air rising from the island.

The big pipe . . .
Canyon Ferry Reservoir provides water used to irrigate farmland in the Helena Valley and also provides some water for municipal use in the city of Helena. Water enters the large pipe shown in the photo. A closer view of the pipe is shown in the photo below. A pump pushes the water up through the pipe, which runs underground to a storage reservoir 7 miles west of the dam. From there a system of canals deliver the water to various parts of the valley for irrigation.

Electricity . . .
Water flows through openings in the dam, drops through large tubes called "penstocks", and turns fan-like devices called turbines. These turbines move huge magnets located near wires, causing electricity to be generated in the wires. The device designed to convert the motion into electricity is called a generator.

Term: convection

#63 - Satellite View of Montana at Night

Last one out of town shut the lights off!
This enhanced satellite view shows the distribution of nighttime lights across Montana. Can you identify the seven cities that have AA high schools (Billings, Bozeman, Butte, Missoula, Kalispell, Helena, Great Falls)? Perhaps you can pick out several smaller communities as well. CLICK HERE to see a recent image of the USA at Night.

Darkness can be a good thing.
The image was provided by the International Dark-Sky Association. The IDA is an organization dedicated to building an awareness light pollution and helping people understand the importance of investing in certain types of lights for outdoor lighting. One reason that the IDA works to promote nighttime darkness is that darker skies make it much easier to view celestial bodies. Even in a state as sparsely populated as Montana both the quantity and quality of what can be seen in the nighttime sky depends on where you are. For instance, someone in Billings will not be able to view auroras or stars nearly as well as someone in Jordan (J). The IDA strives to preserve dark skies in order to enhance viewing of the nighttime sky for everyone, and it believes that one key is for cities like Billings to select types of outdoor lights that minimize light pollution.

Centers.
Although Lewistown (L) is the geographic center of the state, Helena (H) seems fairly well-centered among Montana's larger cities. The "middle of nowhere" distinction would have to go to Jordan (J), a speck of light in the center of eastern Montana surrounded by miles of darkness.

Urban Sprawl.
Notice the area extending south from Missoula (M). This line of lights marks the location of the Bitterroot Valley. Lolo, Florence, Victor, Stevensville, Corvallis, Hamilton, and Darby are all located in this rapidly growing valley.

Term: urban sprawl

#64 - Jupiter's Four Large Moons

Grab your binoculars. . .
Many of those bright points of light that we call "stars" are not stars at all. Some are planets, many are distant galaxies, and others are clouds of gas and dust called nebulae (plural for nebula). Although you can't always see them, Venus, Mars, and Jupiter (planets - NOT stars) are three of the brightest objects in the night sky - However, they aren't always in the right place for us to see them. When this picture was posted in March of 2004, it was an especially good time to see Jupiter. To find out what planets are currently visible in the night sky, CLICK HERE. IF in fact Jupiter is visible, check it out with a good pair of binoculars - You should be able to see some of its four large moons. Jupiter had 95 officially recognized moons as of March 2025, but the first four (the big ones) were discovered by Galileo in 1610. They are named Io, Europa, Ganymede, and Callisto.

Jupiter at its best . . .
The best time to see Jupiter is when it is at opposition. This happens when it is on the side of the Earth opposite the Sun. When it is opposite the Sun, Jupiter is visible all night, rising in the east in the evening and setting in the west around sunrise the next morning. On the other hand, when the Earth and Jupiter are on different sides of the Sun, Jupiter cannot be seen for months.

To find our where the planets are in relationship to the Sun (and each other), CLICK HERE, set the "size" at 1000, and then select "update".

Galileo rocked the boat . . .
Upon hearing at age 40 that a Dutch optician had invented a glass that made distant objects appear larger, Galileo crafted a telescope and began to look at the heavens. His discovery of the moons, along with other discoveries, revolutionized astronomy and challenged some of the religious and philosophical views of the time. Galileo's report that Jupiter is orbited by moons contradicted the geocentric theory, which held that the Earth was the only center of motion in the universe. With his telescope, Galileo also found that Venus went through phases like our Moon; a phenomenon that could not be explained in terms of an Earth-centered system. Furthermore, his discovery of sunspots showed that it had "blemishes," countering the Aristotelian view that the Sun was perfect. In his old age Galileo was forced by The Inquisition to recant his belief in the Copernican (heliocentric) Theory that the planets orbit around the Sun.

Term: The Inquisition, heretic

#65 - Which town has the coldest winters?

A dubious distinction . . .
The map shows the location of four small towns known for their especially cold winter temperatures. Quite often the nightly news reports that one of these towns has recorded the coldest temperature in the state during the previous 24 hours. But which one earns the distinction of having the coldest winters?

Climate factors . . .
Climate is the "average weather" experienced at a location over a period of years. Of course there is much more to climate than just temperature. Humidity, the type and timing of precipitation, cloud cover, seasonal change, and wind are also important considerations. Each of these "symptoms" of climate is influenced by various combinations of the climate factors listed here.

latitude . . . . . . . . . . .elevation

prevailing winds . . . . . . .the shape of the land

nearby ocean currents . . . . distance from large bodies of water

Which climate factors? . . .
For the towns in question a few climate factors must be taken into consideration. Elevation is a huge influence when it comes to temperature. Towns located at higher altitudes tend to have colder temperatures than towns at lower elevations. Here are approximate the elevations of the towns in question (given in feet above sea level).

Wisdom: 6,100 ft. . . . Westby: 1,900 ft. . . . West Yellowstone: 7,000 ft. . . . Cooke City: 8,000 ft.

Another consideration is latitude. Obviously Westby is the farthest north of the four towns. A third consideration is prevailing winds. In Montana the wind usually blows from the west, southwest, or northwest. Since winds are names by the direction that they are coming from, our wind belt is known as the "westerlies".

And the winner is . . .
Despite the fact that it sits at a much lower elevation than the other three towns, over the past 30 years Westby has experienced the coldest winters in Montana. Although Cooke City edges out West Yellowstone as the coldest town based on year round temperatures, Westby's winter temperatures average about 5 degrees colder than the nearest competitor (see yellow lines on the graphs below).

The Canadians are coming . . .
Westby's distinction is due to a combination of latitude and prevailing winds. Since Westby is farthest north it gets less solar energy in the winter than the other towns. More importantly, its location in the northeastern corner of the state also means that Westby is the town most likely to experience air masses that move in from Canada (see map to right). As this cold air moves southward the westerlies often prevent it from reaching western and southern regions of the state.

Climate graphs (below) . . .
The yellow line on these climate graphs show that Westby has a greater annual temperature range than Cooke City. Locations that are closer to the center of continents tend to have hotter summers and colder winters than places that are closer to large bodies of water. Water warms more slowly than land during the summer and it also cools off more slowly than land during the winter. This is why Bismarck, North Dakota has hotter summers and colder winters than Seattle. Although the ocean is not a huge influence in Cooke City, it is more likely to influenced by air from the Pacific than Westby is. In the winter Maritime Polar air from the Pacific is cool and moist compared to the cold, dry Continental Polar air, and the bitter cold Continental Arctic air that often moves into northeastern Montana.

. Term: annual temperature range