EPHEMERAL TRIBUTARY TO ROSEBUD CREEK
Sweedland Ranch
Site # MY - 5
The site is upstream from the first bridge north of the mapped stock pond, which is on the east side of the road. The bridge is 8.9 miles south of I-94 on highway 447, or about 36 miles north of the turnoff from highway 315. The road turns north off 315 immediately east of the Rosebud ridge. The owner, Sweedland, lives about a quarter of a mile south of the bridge on the west side of the road in the only house in sight.
Directions measured with a Brunton are followed by a (B), all others were found using plane table date. Distances measured with a tape are followed by (T), all others were found using the alidade. Compass compensation is 15.5°. ML refers to Maxfield and Landry, 1973, University of Montana, unpublished field notes, site #11.
The primary reference (P.R.) is the tree closest to the stream in an isolated triangle of trees on the left bank, approximately 50 m. upstream from the bridge.
The secondary reference (S.R.) is the first telephone pole south of the P.R., on the left bank.
The tertiary reference (T.R.) is the large tree on the left bank, approximately 90 m. southeast of P.R., closest to the cut bank. Its trunk is bending in almost a right angle from a point approximately 1.5 m. from the ground. It has a single trunk.
BM 2a is located on the terrace approximately 1 m. above the location of BM 2, on the straight line BM 1 to BM 2 to BM 2a.
We could not find BM 4 (established by M and L, 1973), but it is approximately on the line BM 3 to BM 4a.
BM 7 is approximately 1 m. west of a major cow path.
See Table 1.
This ephemeral stream reach was dry except for several muddy puddles. (There have been two or three thunder storms in the area during the past week.) Along the stream reach, a gravel-veneered bed alternates with finer material, which consists of approximately 2/3 gravel and the remainder sand-silt-clay. The coarse and fine-grained areas alternate in a manner similar to Riffles and Pools sequences.
The low terrace (floodplain?) upon which benchmarks 1, 2 and 4 are located was flooded this spring (summer?) as evidenced by one or two cm of fresh fine sand and silt on this terrace. The upper terrace, upon which benchmarks 5, 6 and 7 are located was not flooded.
Cutbanks in the meanders of cross-sections BM 5 to 6 and BM 7 to 8 have both been undercut and have slumped this year.
Many of the gravely reaches of the stream bed have a surface veneer of 2 to 4 cm diameter gravels underlain with 1 cm gravels and sand.
This area is used for grazing, but does not appear to be overgrazed, nor are the stream banks excessively knocked down by cattle. There are no trees growing at the stream's edge. One willow (20 Ft. tall), primary reference, grows about 3 meters from the channel.
The highest cut bank (at cross-section BM 7 to 8) exposes one meter of medium-fine sand immediately under the soil. This is underlain by 0.5 to 0.7 meters of gravel (1-4 cm in diameter) with some imbrication which indicates a flow direction similar to the present flow path.
Site # MY - 5 was surveyed 3 August 1975.