Located in Marion County, Oregon, S-M-S No. 1 is a privately owned earth dam constructed in 1966 for recreational purposes along the Pudding River, a tributary to the Willamette River. With a dam height of 30 feet and a structural height of 32 feet, the reservoir created by S-M-S No. 1 has a storage capacity of 57 acre-feet and covers a surface area of 4.6 acres.

Managed by the Natural Resources Conservation Service, this dam has a low hazard potential and is classified as "Not Rated" in terms of its condition assessment. With a normal storage capacity of 52 acre-feet, the dam has an outlet gate in the form of a slide (sluice gate) and a maximum discharge capacity of 25 cubic feet per second. The last inspection of S-M-S No. 1 was conducted in October 2020, with a scheduled inspection frequency of every 6 years.

Although primarily used for recreational purposes, S-M-S No. 1 plays a role in water resource management and contributes to the overall hydrology of the region. Its presence along the Pudding River showcases the intersection between human-made infrastructure and natural water systems, highlighting the importance of sustainable dam operation and maintenance in the face of changing climate conditions.