Lock and Dam No. 3

{{Infobox dam

| name = Lock and Dam No. 3

| image = Lock & dam -4.jpg

| image_caption = Mississippi River Lock and Dam No. 3

| location_map = Minnesota

| name_official =

| dam_crosses = Upper Mississippi River

| res_name = Pool 3

| location = Red Wing, Goodhue County, Minnesota / Diamond Bluff, Pierce County, Wisconsin, United States.

| operator = 24px U.S. Army Corps of Engineers, St. Paul District

| dam_length = {{convert|365|ft|m|1}} (movable portion)

| dam_height =

| dam_width_base =

| construction_began = {{Start date and age|1935}}

| opening = July {{Start date and age|1938}}

| res_capacity_total = {{convert|1110000|acre feet|km3|abbr=on}}

| res_catchment = {{convert|45170|mi2|km2|abbr=on}}

| res_surface =

| coordinates = {{coord|44|36|36|N|92|36|37|W|type:landmark|display=inline,title}}

| extra =

}}

Lock and Dam No. 3 is a lock and dam located near Red Wing, Minnesota on the Upper Mississippi River around river mile 796.9. It was constructed and placed in operation July 1938. The site underwent major rehabilitation from 1988 through 1991. The dam is {{convert|365|ft|m|1}} long with 4 roller gates. More than {{convert|2000|ft|m|1}} of earth embankment with a series of upstream spot dikes completes the structure to create Pool 3. The lock chamber is {{convert|110|ft|m|1}} wide by {{convert|600|ft|m|1}} long. The lock and dam is owned and operated by the St. Paul District of the United States Army Corps of Engineers-Mississippi Valley Division.

Many types of vessels use the lock which annually passes more than 11 million tons of cargo, including farm products, chemicals and crude materials as the main items shipped. Each year more than 20,000 recreational craft use Lock 3, making it one of the most popular locks on the river. Also, a number of boats involved with fishing tournament utilize the lock.

align="center" |File:Lock and dam 3.jpeg |295px