Florissant Scientific Society


Images From Some Past FSS Field Trips


Trip leaders: Paul Martz, Headwaters Geological Consulting and Tim Brown, Anglo Gold, Cripple Creek

The Poncha Springs meteorite impact structure is an approximately 14 miles in diameter event which occurred at about 12 Ma.   The central rebound core is marked by the development of intense shattering and mega-breccia formation. A marked contrast in deformation between the core and the surrounding basement rock is present.



10:00 AM Meet at Carl’s Jr, Florence, CO. Drive 10 miles to Wetmore via CO-67, then 14 miles to Rosita Road via CO-96. Then 4 miles on Rosita Road to

STOP 1. All of the sites today can be reached by any car or truck. STOP 1 View of Rosita Hills - Mt. Tyndal1, Bassick mine, Game Ridge, Mt. Robinson, Dutch Flat, Bunker Hill

STOP 2 Game Ridge Mine & Mill Site - Game Ridge mine, Game Ridge mill site, aerial tramway connected mine on ridge with mill below. 40 stamp mill built in 1882. Made only test run of ore. Little source of water. Extensive stone walls and foundations remain.

STOP 3 GW mine - Site of first filed claim in Rosita and Custer County in 1872. Custer County was then Fremont County. Discovered by Richard Irwin. He died in 1907 and is buried in Canon City. Also site of Cymbeline claim on same date by Irwin.

STOP 4 Pocahontas-Humbolt Vein Mines - Virginia, Humbolt, Pocahontas, East & West Leviathan, Shephen & Leavenworth mine. Extensive dumps no structures exist except for some headframe timbers. Richest mines in the Rosita area. They were worked as late as the 1920s.

STOP 5 Rosita Townsite - County Seat 1877 - 1882. Great fire of 1881. No original buildings remain.

STOP 6 Pennsylvania Reduction Works - Built 1876 - 1883. Burned down. Extensive stone walls remain. Had 10 stamps and employed 15 men. Second reduction works in area. Freighting costs to smelters outside Rosita before this reduction works was about $50 per ton by wagon.

STOP 7 Rosita Cemetery - Historic cemetery with many old burials. Carl Wulsten leader of the 1870 German Colony and area mine operator is buried here.

STOP 8 Perlite mine - LUNCH BREAK

STOP 9 Rosita Reduction Works - First reduction works in area. Site is just west of the Maverick (Senator) mine site. 2

STOP 10 Polonia and Twenty-Six mine - Located in Poverty Gulch were the Polonia and Twenty-Six mines. They worked the same vein. Extensive dumps.

STOP 11 Julianna mine - Site of Julianna mine. Extensive dumps. Worked 1881 -1884.

STOP 12 Robinson Plateau Road - Toledo mine site. This mine had a small volcanic pipe, with low grade gold ore, similar to Bassick pipe. Mine developed by to levels to 220 feet. Also site of the real estate development of 1902 known as Custer City. Custer City was started by a real estate developer in April 1902. An initial contract was let for the construction of 32 buildings and a hotel. The town was named after General George Custer. There was a statue of him on the site on a granite base. Part of the granite base still remains, but nobody knows what happened to the general. Custer’s widow and Buffalo Bill were supposed to be at the opening, but they didn’t show up. Gov. James Orman gave a speech.

STOP 13 Bassick mine - View of the Bassick mine site and Querida from the Robinson Plateau Road.

STOP 14 Bassick mine - Bassick mine and mill site, Querida Townsite. Nearby was the Bassick Extension mine. Above the Bassick mine volcanic pipe outcrop was the P&O mine. Bassick discovered the outcrop in 1877 and sold the mine in 1879. The Bassick Mining Co. operated it until 1885, when it got into serious financial troubles, which were followed by several legal law suites which lasted until 1898. It was a nice high grade ore body, which the mining company tried to turn into the large mine, however the ore body became smaller and lower grade with depth. Extensive stone retaining walls remain. Hoist and compressor stone foundations also remain. Large main shaft is capped with concrete slabs. Mill level tunnel entrance has steel door. This is the tunnel through which the mine was worked after initially using whim at the outcrop. This was the only mine in the area which produced substantial amounts of gold ore.

STOP 15 Terrible mine - The ore of this mine was exclusively lead carbonate. A large open pit and extensive mill tailings remain. A few remaining foundations from the local community of Isle remain. Mine was developed by a 700 feet incline shaft. It was opened from 1877 - 1943. Joseph R. De Lamar was the first superintendent of the mine. He left the mine in 1885 and went to De Lamar, Idaho, where he developed the famed De Lamar mine. After extracting millions from the mine, he later sold it to an English firm for $463,000.

4:00 PM Travel to Westcliffe Motel 3


9:00 AM Leave Wescliffe Motel

STOP 1 Geyser shaft - To get to the shaft site, we need to use 4-wheel SUV or pickup trucks. We can car pool from the bottom of the hill if necessary and there are plenty of locations for people to leave their cars temporarily. This shaft site probably has the best preserved example of a stone foundation for a flat rope reel steam hoist that exists in Colorado. The shaft itself is capped with concrete slabs. There are extensive dumps. Below the dumps are the remains of the surface mining from the original Silver Cliff and Racine Boy mines. Shaft started in 1887 and work was terminated in 1911. No commercial ore was found. From this site you can see the Plata Verde mine on the south side of Round Mountain and the stone foundations below the mine at the base of the mountain. There was a short aerial tramway that connected the mine to the mill.

STOP 2 Silver Cliff mills - Just west of the Silver Cliff and Racine Boy surface mine site are the stone foundations of the two 40 stamp mills built to treat the Silver Cliff ore. Also you can see the trace of the rail tram track that connected the mine with the mills.

STOP 3 Silver Cliff Cemetery - Located about 1 mile south of Silver Cliff are the Silver Cliff Cemeteries, one Catholic and one for all others. Nine of the victims of the 1885 Bull Domingo mine fire were buried here. I have found only two of the grave markers (Patton and Westfall). One other victim was buried in Wisconsin. We will omit this stop if there is no interest). There is no cemetery in Westcliffe.

STOP 4 Bull Domingo mine - Located several miles north of the Geyser is the famed Bull Domingo mine. This mine site has been off limits on and off over the past few years so it is uncertain if we will be able to reach it. If we can get in, we will all need to travel from the main dirt road to the mine (about ½ mile) in 4-wheel SUV or pickups trucks. There are a few stone foundations on the site. Many pieces of broken glass, tin cans etc remain as there were a number of houses at the mine as well as mine buildings. The ruins of a wooden ore bin from the 1910s remains at the site. The ore deposit was a pipe or vent like deposit similar to that of the Bassick except that the pipe is formed in pre-Cambrian rocks (that is in excess of 500 million years old). The Bull Domingo mill was located along Grape Creek some 3 ½ miles by wagon road. STOP 5 Lady Franklin mine - Two rather beaten headframes exist at this site. One of the last mines to operate in the area as some ore was mined during WW II. 4

STOP 6 Song Bird and Gray Eagle mines - Two collapsed shaft collars and dumps mark the location of these two mines. Produced some ver y high grade ore in the 1880s.

STOP 7 Ben West Volcano - The hill just south of the Song Bird-Gray Eagle site is called Ben West Hill and is all that remains of the original volcano which deposited the volcanic ash that formed the majority of the tuff and breccia rocks in the Silver Cliff Area. Just west of Ben West Hill are the capped shafts of the Herman and Passiflora mines. These mines were primarily lead, silver and copper producers and operated between 1914 and 1953.

STOP 8 King of the Carbonates - Operated between 1880 - 1935. Large dumps and mill tailings exist at the site. Was a lead and silver producer.

STOP 9 Defender mine - The last underground metal mine to actively operate in the Silver Cliff area. Operated between 1938 and 1955. Developed by a incline shaft. Headframe and hoist building still standing. STOP 10 Adelia Mill - The Adelia mill was a custom 10 stamp mill, built along Grape Creek. Operations began in 1880 and was operated until at least 1887. It milled ores from the Silver Bar, Hecla and Kate mines. Initially it used amalgamating pans, but later installed jigs.

1:00 PM End of tour. Lunch on your own. There are several museums in the area, but it is unknown if they will be open as there schedules are rather irregular. The old fire house in Silver and some old fire equipment (hose cart) and some mining artifacts. The old 1891 school house in Westcliffe is an excellent museum. I will point out where these are and you can visited them if time permits.

Revised 4/3/2009

Tentative Schedule of Future Events

August 25




Gathering will be at Don McGookey's cabin outside of Fairplay, as usual at noon. Special guest speaker will be Larry Frank telling about the History of the Oliver Twist Tunnel up on Mosquito Pass. Depending on conditions, it may be possible to take 4-wheel drive vehicles up the pass.

Denver Gem & Mineral Show - https://www.denvermineralshow.com/ the minerals of Canada.

Tour of the Colorado Springs coal field * by Tim Brown and Chris Carroll.


On September 23 2018, Alex Paul took us on a field trip to Pikes Peak to view the effects that past glacial periods had on this area. Click on the links below to watch the video, download the PDF or view more pictures from this trip.

Watch: The Video

Download: The PDF

View: More Pictures

Indian Springs

Indian Springs is considered the best locality to study Ordovician Period trace fossils in North America because of the excellent preservation and wide variety of ichnospecies, or types of trace fossils, found there.

For additional information on this site see:




   Visit the FSS YouTube channel for more.

See more on the FSS Facebook Page.

Scratch Mark

Marshall Mesa, Iron Furnace and Dinosaur Tracks

On June 30, 2019 we took a field trip to Marshall Mesa to see the historic iron blast furnace and the newly discovered dinosaur and tortoise tracks.


Watch: The Video

Download: The Poster PDF

View: More Pictures

Culturally Modified Trees - John Anderson

On July 21, 2019, John Anderson gave us a tour of the Culturally Modified Trees around the Glen Isle Resort.

Watch: The Video

             John’s TEDx talk

Read: Beth’s Colorow Article

View: More Pictures

Visit: NASTaP

         Glen Isle Resort