Rockd by Walnut Hills

This is going to sound like an advertisement...consider it a recommendation.

Rockd by The Mactostrat lab at the Geoscience department at the University of Wisconsin - Madison is one of my main tools for geological exploration. It's an app on my smartphone. 

Where most geology apps are reference works, like geology textbooks or encyclopedias on your phone, Rockd is equipment. It includes a Brunton compass and information about localities with topographic and geological maps and geology and paleontology profiles. It's pretty impressive how much local information it packs. (The Brunton compass needs a gyroscope and magnetometer to work.)

Let's see what it says about my backyard, Walnut Hills in Centennial, Colorado.

When I open Rockd, I see this, my dash board.

It gives me an overview of my area. 

People that don't live here often mistake Denver for a mountain town. It may be a gateway to the Rockies but it's situated at the western edge of the Great Plains. It's hilly grasslands.

Specifically, Centennial, a town in the Denver metro area, is near the western edge of the Colorado Piedmont region. 

Denver makes a big deal about being the Mile High City but, actually, it's down in a hole carved by the South Platte River. Just about everyone around us is at higher elevations.

We're sometimes called the "high plains" but, technically, the high plains are to the east of us. As explained by Rockd, when I tap the Colorado Piedmont panel, the high plains were formed when the Colorado Plateau was pushed up when the Pacific plate crashed into (and is still crashing into) North America. The Rockies are still growing but erosion is happening faster and the craggy appearance of the Rocky Mountains is due to the deep cutting of millions of years by rain, frost, wind, and chemical action. All the debris that washed out of the mountains piled up to form the high plains, and then streams running from the mountains started cutting the softer sediment down to form the Colorado Piedmont.

How old is the rock around here? Rockd says 0.0117 mA (that stands for "mega annum" or million years) to present. This is fairly new stuff. The late pleistocene began 0.02 million years ago and the Quaternary is the most recent age of geologic time. You probably know that the continents have shifted around a lot in the past. Here's what Rockd says the World looked like in the Quaternary age.

Same as today. Really new stuff.

The colluvium mentioned is "generally unconsolidated material deposited on slopes by gravity and sheetwash". (The original source sited is Trimble, D.E., M.N. Machette, 2003, Geologic Map of the Greater Denver Area, Front Range Urban Corridor, Colorado: U.S. Geological Survey Geologic Investigations Series 1-856-H.

(If I poke the citation, Rockd carries me to the actual paper.)

The layer of colluvium is generally more than 1.5 meters thick. Mind you, that's our bedrock. Above that is the regolith. Regolith is the term for the bedrock after it rots. We have a lot of debris under our feet..

It's sort of hard to tell if the stuff in the Little Dry Creek stream bed is native or if it was placed there to slow erosion, or if it has been washed down from architectural fill upstream, but it could easily be part of the colluvium washed out of the mountains long ago. Some of that is pretty chunky.

So, we're at 5732 feet. Littleton is right on the river at 5351 feet. We're situated right at the top of the rim of the South Platte River valley, which makes the valley 381 feet deep here. The river comes out of the mountains due west of both us and Littleton at Waterton Canyon. Water flows downhill so Denver, through which the South Platte flows is lower in elevation at 5130 feet (Wikipedia says 5139-5690 feet but that would be the whole Denver metro area.)

Here's a geologic map of the area from Rockd.

The lighter stuff is the colluvium I've been talking about. The darker is Dawson formation which is an older Late Cretaceous to Paleocene rock...100.5-56 million years old. It might be worth visiting the next neighborhood over to see if Willow Creek digs into that sandstone.

Most of the fossils listed in this area are nearer the bottom of the river valley, so I don't expect to find any in this neighborhood (though I will look for some microfossils in the creek bank), also most of the minerals will be clays and quartz since most of the other stuff would have broken down long ago.

Rockd is a free download, so install it and see what it has to say about your area. You might be surprised.

--- Highline Canal: Winter ---

Before I even get started, let me warn any through hikers on the Highline Canal Trail that there is currently no easy way around Plum Creek on the trail. You can walk a long way up Titan Road and north on Santa Fe, both heavily trafficked much of the day with little shoulder to walk on, or you can walk across the entire width of Chatfield Lake State Park, a large and hilly expanse, to Mineral Road and take the Mineral Trail up to reconnect the the Highline Canal. As detours, I wouldn't recommend either although Chatfield State Park and the little parks along the South Platte River are at least scenic.

I took a Lyft to the Colorado Trail trailhead Thursday, February 28 with the intention of walking 18 miles to the Elati Street trailhead of the Highline Canal, but, as the very nature of adventures is to throw curve balls, I only made it seven or eight miles (maybe further after wandering around looking for a way around Plum Creek). I did, nevertheless, enjoy the hike. I realize that the Rolling Stones were correct - "You can't always get what you want."

Expecting a long walk well into the night, I got up at 6:00 and was out as the sun was rising.

                                                                    [Sunrise]

By the time I reached the trailhead across from the Kassler Center in bright daylight. The foothills were gorgeously speckled with patches of snow from the big snowfall the weekend before.

                                                          [Kassler Center at Waterton]

My plans required a short roadwalk south along Waterton Road to the canal. The Lockheed-Martin plant is ever visible through the first stretch of the trail to Plum Creek.

                                                              [Lockheed-Martin]

It doesn't snow constantly in Denver during winter but it does enough that there is usually snow on the ground. This is probably a pretty typical view of the South Platte in the winter.

                                                   [South Platte at Waterton Road]

There is a reservoir, the Platte Canyon Reservoir,  at the Waterton Road Trailhead that draws water off the canal for storage. It seems to be popular for water birds. I hope these like the ice.

                                             [Platte Canyon Reservoir pumping station]

                                                        [Lockheed Martin, again]

                                                               [Highline Canal]

                                                          [Platte Canyon Reservoir]

[Birds - look like gulls to me, there were also ducks but they were too far out for a photograph]

The first few hundred meters of trail were paved and the canal was dry except for stretches that ran with snow melt.

                                                             [Snow on the trail]

I saw a lot of this rosy leafed plant on the side of the trail. I'm pretty sure that it would have been green during the summer and I'm not sure what it is - maybe a potentilla? I thought it was a red moss at first. Out of all the wildflowers, I think I like the belly flowers most. Those are the ones you have to get down on your belly to see. They are often some of the most intricate, colorful blooms. I'd like to see what the flowers on these look like.

                                                                  [Belly flowers]

Much of the Highline Trail in this area runs through private properties. There are a lot of horses and cattle.

                                                                 [No Trespassing]

This ranch has a log cabin on its grounds.

                                                                   [Log cabin]

And, here, the canal actually looks like a canal with snow melt.

                                                              [Highline Canal]

The power lines that cross the Highline Canal carry lots of juice to Lockheed-Martin which could be considered the gateway to space, since they build rockets.  Denver is very space conscious. The School of Mining in Golden has begun a focus on technology to mine asteroids, for instance.

                                                                  [Power lines]

The trail along the boundaries of Chatfield Lake State Park affords great views of the Front Range. The hills in the foreground hide Conifer and the one in the middle distance is Mount Morrison. Further back is the mountains around Golden and Green Mountain.

                                                            [Front Range]

I didn't see a lot of wildlife (or tracks), but I saw or heard many hawks, like this fellow,

                                                                        [Hawk]

and this herd of deer. They seemed to be used to two-legged pedestrians.

                                                                        [Deer]

This area makes it clear that the high plains butt right up against the Rockies. There's very little transition.

                                                           [Plains and mountains]

On the Highline Canal Trail, mileposts are your friend. They appear every mile and mark mileage from the Waterton end of the trail.

                                                                         [Mile 6]

My original intention was to follow the Highline Canal Trail to the Plum Creek entrance to Chatfield Lake State Park and pick up the Chatfield Internal Trail in the park which meets back up with the Canal Trail on the other side of Plum Creek. Unfortunately, the construction in the park has obliterated the eastern end of the Internal Trail, so Chatfield was the end of the line for this hike.

The views around the lake are nice (if you don't look in the direction of the construction). The water is down considerably and this is definitely high plains.

                                                                [Chatfield Lake]

As advertised (in the Highline Canal Guide), the Denver skyline is visible from the park but, on this day, there was a gray-brown haze around the city that wasn't very photogenic, so I passed that picture up.

The end of my adventure was a long wait at the parking area at Roxborough Road. I won't go into detail about how my phone's battery died at a crucial point and I had to finagle a way back home, but I will say that the other hikers and the Douglas County Sheriff's Department are great and that Call Box at the parking area? It works.

If you live in the Denver area or will be visiting, you might want to check out the 71 mile long urban Highline Canal trail. The canal is a weird tributary of the South Platte that flows away from the river and crosses roads and other streams. You can check it out on the Internet here:

https://highlinecanal.org/?gclid=Cj0KCQiAk-7jBRD9ARIsAEy8mh7NOCA8cED47AFcPvdeZSZuYmsjlSTWE7lFOsSZYl5O50VeH13cj5gaAtGhEALw_wcB

How's winter in your area? Do you have snow? Are there plants that are especially adapted to your winters? Does the wildlife behave differently?

--- Field trips, hikes, and endurance hikes ---

2016

I made the decision to let go of my van back in 2014 and I haven't really regretted the decision. There are some down sides. If I leave the house, I do so on foot (unless it's a group activity, and those are fairly rare) and I'm limited to how far I can walk in a day or two or how many bus tickets I can afford, and the money has been rather scarce since I moved to south Denver.

But, on the whole, I prefer walking to driving for reasons I've mentioned. Most importantly, I miss too much when I'm driving.

There are three kinds of walking I regularly do.

Field trips have an end goal. I walk to get somewhere and do something at the farthest point of the walk. That might be a museum, a point of interest, or an activity, like a street festival or market. I guess my regular grocery runs could be called field trips.

For a hike, the walk is the goal. I regularly walk Bear Creek Trail, looking for particular things along the way. I rarely walk to Morrison to see something in Morrison. Morrison is only part of the reason for the walk.

Once or twice a year, I take endurance hikes - particularly long or grueling hikes. I joke that it's my annual stress test. I have a heart condition and I'm not sure how much it really effects me. The only thing I can say for sure is that working in a horizontal position or on an upside-down incline doesn't work too well for me. I figure that, if I can survive one of these endurance hikes, my heart must be in pretty good condition.

But, to be honest, I just like pushing myself occasionally. I've been doing this for some time. I met my long-time hiking friend, Paul Holm, in the early 70s in a biology class at Auburn University. Our first distance hike was a walk from the West Point exit of I85 at the Alabama-Georgia state line, across Pine Mountain, to Warm Springs, Georgia, a distance of over 27 miles. That was the longest day hike we took. The Dreaded Mid-Summer Death Hike became a tradition.

Our last long hike together, before I moved to Colorado was from the southern terminus of the Pinhoti Trail in Alabama about seven miles up and across Rebecca Mountain. It was a hot, dry day that improved when a line of thunderstorms moved in. When we were almost back to the cars, we found a patch of particularly juicy blackberries. That, by itself, made the pain worthwhile.

At the end of the hike, he went back home and I drove up to Mount Cheaha to camp over night. I ate at the restaurant on top of the mountain (one of my favorites), and the next morning, I checked out the Kymulga Covered Bridge, between Sylacauga and Talledega, and went to First Baptist Church in Sylacauga for Sunday School and the preaching service. After that, I drove back to Auburn and spent the rest of the day hiking and dining out with Paul.

Since moving to the Denver area, I've kept the tradition every year. In 2014, I walked from home in Broomfield to Flatirons Junction and then up the Coalton Trail, almost to the Flatirons before returning home. It was almost exactly a 12 hour walk with few short stops, so it was between 38.6 kilometers (24 miles) and 58 kilometers (36 miles). That hike was all high plains.

After moving to South Denver in 2015, I walked from home to Kipling Trail and from there up to Jewell Avenue; then I headed west to Green Mountain and across Dinosaur Ridge to Red Rocks park. A short road walk brought me to Morrison and Bear Creek Trail, which brought me back home.

After it snows a couple of times, I plan to walk to Waterton Canyon, which is south of the Denver area. One of my packmates works at River Point Shopping area, at the head of the trail system that leads to Waterton so I can start very early and cut off the Bear Creek portion of the hike. Still, it'll be well after dark before I get back home.