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Wyoming History

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Lincoln Highway

Part six of seven parts

Part 1

Part 2

Part 3

Part 4

Part 6

Part 7

Continue to References

 

Fort Bridger State Historic Site

 

Results

Shovel test units

A total of ten (10) test units were excavated by shovel in the area immediately to the front of cabin units ‘5’ through ‘8’. The shovel test units were square shaped and 35 cm wide on each side. The area excavated in this manner was 12,250 cm², or 1.225 m².

The shovel test units were established upon a grid system based on a line designated as 120N and centered alternately between the 120E and 121E lines, and the 121E and 122E lines. Unit provenience was recognized through designating each northeast corner as the control corner. By using this method the extent of shovel test excavation reached to the 139N line. Depth was measured from the present ground surface to the overall bottom of each shovel test unit.

Shovel test unit ‘1’ was excavated as a one meter-by-one meter unit and will be included with the descriptions for those particular test units.

Individual shovel test unit descriptions are as follow:

 
Shovel Test Unit 1

Shovel Test Unit 1 was first intended to be a probe. Because of what was encountered during excavation this became Excavation Unit 1 and is described below.

 
Shovel Test Unit 2

Shovel test unit 2 was a 35cm x 35cm square excavation centered within the unit 123N 121E. Overall depth for this unit was 61cm below the present ground surface.

Matrix was a homogeneous, dark brown, medium grained sandy loam throughout the entire uppermost 40cm. Clay content was determined to be in the 5% to 15% range with a high organic content. A few (n = <5) small rounded cobblestones were present in the matrix distributed in a random manner throughout the unit’s vertical extent. Matted grass roots were noted in the uppermost 3cm to 5cm and horizontally running tree roots (Populus) were present within the entire unit.

At 40cm to 61cm below the present ground surface the matrix changed to being one of a light to medium brown, well sorted, medium grain alluvial sand containing no cultural material.

Cultural material recovered was within the uppermost 40cm exclusively, and consisted of small green and brown glass shards, and a single small saucer or plate rim sherd.

No structural features were encountered while excavating this test unit.

 
Shovel Test Unit 3

Shovel test unit 3 was a 35cm x 35cm square excavation centered within the unit 125N 122E. Overall depth for this unit was 40cm below the present ground surface.

Soil was a uniform dark brown sandy loam of a well sorted, medium grain nature, with the uppermost 9cm containing a highly matted network of fine roots emanating from surface grasses. Tree roots (Populus) were numerous from 26cm below the present ground surface to the overall bottom surface.

Within the lowermost 24cm (16cm to 40cm below the present ground surface) was a moderate concentration of jumbled cobble rocks ranging in size of from 3cm to 8cm in length.

At 40cm below the present ground surface the top surface of a light to medium brown alluvial sand horizon was exposed and excavation ceased.

Recovered were iron fragments and pieces of coal.

No structural features were encountered while excavating this test unit.

 
Shovel Test Unit 4

Shovel test unit 4 was a 35cm x 35cm square excavation centered within the unit 127N 121E. Overall depth for this unit was 70cm below the present ground surface.

Soil was composed of a dark brown, medium grain, well sorted sandy loam with the uppermost 6cm containing a highly matted system of roots emanating from surface grasses. A few small sized, horizontally oriented tree roots were encountered in the matted grass layer and fewer in the subsequent cobble rock concentration. 

A dense concentration of rounded cobble rocks, varying in size from 6cm to 30cm in length, were distributed in an unorganized jumble throughout the unit from 8cm below the present ground surface to the bottom. The soil containing the rounded cobble rock concentration was a well sorted sandy loam, but was noted as slightly darker than that within the grass matte layer.

The matted grass layer held shards of clear plate window glass and within the jumbled cobble rock layer were found additional colored bottle and clear decorated glass shards together with a small number of cut nails and a mother-of-pearl button.

No structural features were encountered while excavating this test unit, but the high concentration of disorganized cobble rocks in this test unit might indicates a previous ground disturbance with a mixture of cultural material associated with occupations prior to, and during the Motor Court era.

 
Shovel Test Unit 5

Shovel test unit 5 was a 35cm x 35cm square excavation centered within the unit 129N 122E. Overall depth for this unit was 44cm below the present ground surface.

A dark brown, organics laden sandy loam made up the soil matrix for this shovel test unit. Soil was uniform and homogeneous throughout.

Uppermost 6cm was a consistent layer of tightly matted grass root material within dark brown, well sorted sand. Other than the grass roots, no intrusions or inclusions were encountered within this layer. Only one tree root, and that of ½” diameter size, was encountered during excavation near the bottom.

Test Unit 5 was characterized by a dense, highly concentrated layer of rounded cobble rocks from beneath the grass matte layer to the overall bottom. The cobbles continued, but less densely, into a light to medium brown colored, well sorted, alluvial sand horizon. Excavation terminated upon exposure of this light colored sand as similar deposits have proven to be non-cultural wherever encountered.

A 2cm to 3cm thick layer of sand and crushed limestone of light gray color was located beneath the matted grass root material and atop the concentrated cobble rock layer.

Small shards of brown, green and clear glass were recovered in a large amount together with a small white glaze earthenware sherd.

No structural features were encountered while excavating this test unit, and the unit has the appearance of having been previously disturbed.

 
Shovel Test Unit 6

Shovel test unit 6 was a 35cm x 35cm square excavation centered within the unit 131N 121E. Overall depth for this unit was 45cm below the present ground surface.

Soil was an extremely unvarying and homogeneous sandy loam of dark brown color and a content of decaying and decayed plant organics. The soil was primarily composed of sand with clay content of no more than 15%.
The upper 4cm of this unit exhibited a layer of matted grass root material; the layer was noticeably more compacted than previous units at similar depths. No tree roots were encountered anywhere within this shovel test unit.
Shovel test unit 6 was dominated by the presence of a highly concentrated jumbled of cobble rocks through the majority of its depth. The largest sized cobbles were in the uppermost 17cm below the matted grass root layer, and existed in smaller sizes and a noticeably lighter concentration into an horizon of light to medium brown, well sorted, medium grain alluvial sand. Excavation terminated upon exposing this lighter brown colored sand deposit.
Cultural material recovered during screening was entirely fragmentary, and appeared to indicate a mixture of from before and during the Motor Court occupation. Artifacts included clear, brown and green colored glass shards, a rubber object, and a white glaze earthenware sherd.

No structural features were encountered while excavating this test unit.

 
Shovel Test Unit 7

Shovel test unit 7 was a 35cm x 35cm square excavation centered within the unit 133N 122E. Overall depth for this unit was 47cm below the present ground surface.

Soil matrix was a consistently dark brown sandy loam throughout the vertical extent of this test unit. The uppermost 7cm was a closely matted collection of grass root material. Only one tree root noted within the entire vertical extent of this unit’s soil matrix, possibly due to the highly concentrated nature of the cobble rocks beneath the grass root matting.

Beneath the matted grass root layer was a poorly sorted concentration of densely packed, unorganized rock cobbles, which extended the remaining depth of the unit. The cobble rock concentration continued into a layer of light to medium brown, well sorted, medium grain sand left unexcavated as it was presumed to be non-cultural.
Recovered were shards of colored and clear bottle glass, clear plate glass, and a fragment of plastic.

No structural features were encountered while excavating this test unit.

 
Shovel Test Unit 8

Shovel test unit 8 was a 35cm x 35cm square excavation centered within the unit 135N 121E. Overall depth for this unit was 43cm below the present ground surface.

The soil matrix remained a consistent and homogeneous dark brown sandy loam, the uppermost 7cm of which manifested a concentration of closely matted grass root material emanating from surface grasses. The clay content did not appear to exceed 15% of the entire matrix substance.

A jumbled, rounded cobble rock concentration began a 13cm below the present ground surface and was not as densely packed as in previous shovel test units. A higher number of smaller sized cobles (L = 2cm to 5cm) were also noted as inconsistent with other shovel test units. Larger sized cobble rocks, those 10cm or longer, were less than 20 in number. Mixed within the uppermost 5cm of the cobble rock concentration were small sized, angular, flat limestone chips.

Excavation terminated upon exposing a layer of light to medium brown colored sand, well sorted and medium grained.

The artifact collection consisted only of dark green and brown glass shards.

No structural features were encountered while excavating this test unit.

 
Shovel Test Unit 9

Shovel test unit 9 was a 35cm x 35cm square excavation centered within the unit 137N 122E. Overall depth for this unit was 41cm below the present ground surface.

The soil was a matrix of well sorted, medium grain, dark brown sandy loam with clay content believed to not exceed 15%. A layer of concentrated grass roots forming a dense matte containing the sand loam matrix. Tree roots were present only within the bottom one-half of the test unit.

Small sized cobble rocks were evident immediately beneath the grass matte root layer. Cobble rocks remained mostly small sized (L = 2cm to 6cm), and in a loose concentration from 3cm below the present ground surface to 26cm below the present ground surface where the cobble rocks became mostly larger in size (L = up to 18cm) and more densely concentrated.

The cobble rocks were still densely packed when the primary matrix transitioned into a light to medium brown, well sorted, alluvial type sand was exposed and excavation was terminated.

Cultural material recovered from throughout the overall extent of this shovel test unit consisted exclusively of green, brown, and clear glass shards. The colored glass fragments were believed to have originated from bottles.

No structural features were encountered while excavating this test unit.

 
Shovel Test Unit 10

Shovel test unit 10 was a 35cm x 35cm square excavation centered within the unit 139N 121E. Overall depth for this unit was 39cm below the present ground surface.

A dark brown, organic laden sandy loam was prominent through the vertical extent of this shovel test unit. A 3cm to 4cm thick layer of matted grass root material was all that overlay layers of gravel and rounded cobble rocks. A small number of horizontally oriented tree roots were present from the midrange elevation to the overall bottom elevation.
Immediately below the matted grass root deposit was a layer of pea-gravel, which became a loose concentration of 2cm to 6cm long cobble rocks and soil matrix. The loose cobble rock concentration transitioned to a densely compacted, yet poorly sorted cobble rock concentration of stones 7cm to 20cm in length. The dense concentration of larger sized cobbles rocks prevented further excavation, and with the exposed presence of a light to medium brown alluvial soil, excavation terminated.

Cultural material within this shovel test unit was small in number and consisted of only a cut nail, an amorphous iron fragment, and a small number of green and brown colored glass shards.

No structural features were encountered while excavating this test unit.

 
1M x 1M Test Units

A total of three test units were excavated in the area immediately to the front of cabin units ‘1’ through ‘8’. A fourth unit was excavated within cabin room ‘2’ at or quite near the floor’s central point. The test units were square shaped and one meter wide on each side. The area excavated in this manner was 4m².
The 1m x 1m test units were established upon a grid system based on a line designated as 120N, and continued between the 114E and 122E lines. By using this method the extent of test excavation reached to the 157N line, or a northward distance of 37 meters.

Unit provenience was standardized through designating each northeast corner as the control corner. Depth was measured from a vertical control point (VCP) set at one marked corner, or as in the case of test unit 157N 118E along the north boundary line.

All test units were excavated according to an arbitrary level system of ten (10) centimeters per level with the first, or uppermost, level designated as Level 1and measured downward ten centimeters from the height of the vertical control point. Successively lower levels were designated with sequentially higher numbers (e.g. Level 2, Level 3, etc.).

Test unit 1 (121N 122E) was excavated as a one meter-by-one meter unit in place of shovel test unit 1 and is included in this portion.
Individual test unit descriptions are as follow:

Test Unit 1

Test unit 1 was a 1m x 1m square excavation with its northeast corner at 121N 122E. Overall depth for this unit was 20cm below the vertical control point at 120N 121E.

Level 1
Soil matrix was a dark brown, well sorted, medium grain, homogeneous sandy loam with clay content determined to not exceed 10%. The uppermost 7cm was of a slightly darker brown color and contained a heavily matted grass root concentration. No tree roots, cobble rocks of any size, or other intrusions or disturbances were noticed.
Matrix remained consistent throughout Level 1with the exception of a lens, or layer of tan colored sand, small sized broken and angular pieces of limestone, and crushed and powdery limestone encountered in the northwestern corner. The lens was roughly semi-circular and extended approximately 61cm southward and eastward from that corner. The lens varied from 2cm to 5cm in thickness and was encountered at the interface between the matted grass root layer and the uninterrupted lower matrix.

Cultural material was also varied and mostly fragmentary consisting of glass, cut nails, amorphous iron fragments, a button and button fragment, and glazed earthenware sherds. The collection within Level 1 appeared to exhibit a degree of cultural mixing from what could be the military and post-military and Motor Court eras.

Level 2
Soil matrix continued as being a continuous dark brown, well sorted, sandy loam. Near the bottom of this level were noted three small tree roots near the bottom and did not disturb any cultural material. No cobble rocks were encountered anywhere within Level 2, and no inclusions other than a small, thin concentration of charcoal lying horizontally near the bottom in the southwest corner.

The cultural horizon terminated at 22cm below the vertical control point and no cultural material was encountered from that elevation to the overall Level 2 bottom surface. Consequently no further excavation was conducted in this unit.

Recovered cultural material consisted of a high number of small glass shards, together with plastic, nail and iron fragments, and structural material fragments.

No structural features were encountered while excavating this test unit.

Test Unit 2

Test unit 2 was a 1m x 1m square excavation with its northeast corner at 121N 114E. Overall depth for this unit was 25cm below the vertical control point at 120N 114E. This test unit was between the rear walls of cabin ‘8’ and the front of a combination generator and latrine building. The unit was positioned directly outside and beneath the main entrance to the latrine.

Level 1
The soil was again a dark brown, organics laden, homogeneous and well sorted sandy loam with the uppermost 8cm of soil contained within a highly concentrated matting of grass root material.

At the elevation of 10.5cm below the vertical control point was encountered a layer of small rounded cobble rocks of length no more than 2cm and highly concentrated immediately to the exterior and beneath the latrine entrance. The cobble rocks were mostly, but wholly, crushed, and this concentration had the appearance of a layer of purposely-laid gravel. The gravel layer was 4cm thick and was concentrated throughout the horizontal extent of this unit, but was most heavily concentrated before the latrine entrance.

The Level 1 portion associated with the matted grass root layer contained only wire nail and nail fragments and coal pieces. Within and beneath the gravel layer were recovered all the glass shards from Level 1 as well as white glazed earthenware sherds.

Level 2

The soil matrix continued to be a consistently well sorted, medium grain, dark brown sandy loam. Randomly distributed within the matrix were a few small sized cobble rocks. A few small sized tree roots were also present within Level 2, but did not interrupt any cultural material or feature.
Cultural material consisted mostly of shattered glass, which decreased in concentration in direct proportion to the depth below the vertical control point until becoming nonexistent by the point at which the bottom of Level 2 was reached.

Excavation in the unit 121N 114E terminated at 25cm below the vertical control point.

No structural features were encountered while excavating this test unit.

Test Unit 3
Test unit 3 was a 1m x 1m square excavation with its northeast corner at 139N 120E. Overall depth for this unit was 32cm below the vertical control point at 139N 120E. The test unit was positioned near the entryway landing and steps at cabin ‘5’.

Level 1
The soil matrix was a well sorted sandy loam of a dark brown color and quite homogeneous throughout the level.
Matted root material from surface grasses was confined within the uppermost 3cm as a high concentration of cobble rocks and gravel impedes root penetration deeper into the level. The matted grass root was intermittent and not at as concentrated as with previous test units.

Beneath the shallow matted grass root layer was a concentration of gravels and rounded cobble rocks. The gravel consisted of both smaller sized rounded stones (L = 2cm or less) and similar sized angular, or crushed stone to the extent of pea gravel or crusher fines. Intermixed was a moderate to high concentration of larger rock cobbles jumbled throughout the gravel layer. The gravel/cobble concentration was not heavy enough as to prevent the sandy loam matrix from being present between the individual stones. Also present was a small, loosely organized concentration of coal in the northeast corner.

Cultural material was noted as being mixed between military and Motor Court era artifacts with a great preponderance of small colored glass shards, modern roofing nails, cut and wire nails, screws, additional unidentified iron pieces, and three dark blue to purple colored seed beads.

Level 2
A dark brown, homogeneous sandy loam matrix continues to dominate. Tree roots and rootlets branching from off the roots were present throughout the level.

The concentration of rounded cobble rocks encountered in Level 1 remains high. Smaller sized cobbles of 5cm or less are the most numerous, yet larger cobbles up to 15cm in length were encountered in a random distribution. The angular crushed gravel remained, but to a smaller degree.
Cultural material was consistent with Level 1, but to a noticeably lesser amount. Finely fragmented colored glass shards were in the greatest amount. Also present were cut nails and nail fragments, unidentified iron pieces, and white glazed earthenware sherds.

Level 3
As artifacts were still present in the soil as Level 2 was completed, excavation continued into Level 3 to determine if a cultural presence was still evident.

The soil matrix remains a well sorted, dark brown sandy loam with a high concentration of assorted sized tree roots throughout the level. 

Cobble rocks of various sizes continue to be highly concentrated and randomly distributed within Level 3. At 30.5cm below the vertical control point, the top surface of a light to medium brown, well sorted sand was exposed and excavation was terminated.

Cultural material was present, but in a much lighter concentration than encountered in either Level 1 or Level 2. Artifact types were consistent with the previous two levels and were composed of finely fragmented glass shards, cut nails, and a white glazed earthenware sherd.

No structural features were encountered while excavating this test unit.

Test Unit 4
Test unit 4 was a 1m x 1m square excavation with its northeast corner at 157N 118E. Overall depth for this unit was 20cm below the vertical control point at 156.83N 117.93E. The test unit was positioned in the interior floor near the center of cabin ‘2’.

Level 1
Soil matrix was a homogeneous of moderately compacted dark brown sandy loam, well sorted, and with high organics content. Tree roots of mostly small size cross through the level in a mostly north to south direction.
The uppermost 4cm of the matrix was a loose amalgam of dark brown sandy loam; broken tree branches and sticks, broken pieces of floorboard, tree leaves and floor linoleum. This mixture formed a ‘duff’ layer, which in turn lay atop the principle soil matrix. Below the ‘duff’ and continuing to the bottom of Level 1 was a continuous dark brown sandy loam with many small and one large tree root running through. Within the bottommost 2cm were pockets of a light to medium brown colored sand.

Among the artifacts recovered in Level 1 were mother-of-pearl and hard rubber or plastic-like material buttons, glass marbles, fabric, a small toy steam locomotive, finely fragmented glass shards, and wire nails and nail fragments.

Level 2
Soil matrix remained a dark brown, organics laden, well sorted, medium grain sandy loam with a clay content determined to be no more than 10%. No stone intrusions were noted except a roughly cube shaped limestone block nearest to the overall center of this unit and underlying a north-south oriented wooden floor joist. The overall concentration of tree root disturbance increased noticeably over Level 1, and parts of this unit and level exhibited a high tree root concentration.

The small pockets of light to medium brown sand encountered in Level 1 have consolidated into one continuous lens positioned in the south-central area of this unit and gave every indication of continuing lower into the soil. The lighter colored sand is consistent with that encountered elsewhere at Fort Bridger as underlying all known cultural horizons and has been noted in other places on-site as being non-cultural.
Cultural material concentrations decreased noticeably from Level 1. Artifacts consisted of a single white glazed earthenware sherd, two shards of colored opalescent glass, and a single cut nail fragment; which, taken together, could indicate a military era origin.

No features were encountered while excavating.

 

 
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If you have any questions please feel free to contact Dudley Gardner.

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