In the spring of 1933, some well known names, George Callenius and Robert Mattice, were standing on the hill which is now the south shore of the lake watching a flood of water coming down the creek and the idea came to them at that time. It was not until July 24, 1935, that enough interest had been created to justify any concrete action in the matter.

A committee consisting of George Callenius, John Fredericks and George Clayton who was commissioned to meet with the State Conservation Commission as to the feasibility and means of securing a lake. It was at this time credit goes to George Callenius for so ably presenting this proposed project.

A resolution created a park board of Dr. C.E. Summy, J.L. Beerman and John Tjossem, who would have the power to purchase and acquire the land for park purposes. This resolution was passed February 2, 1935. An election was held on the proposal to issue and sell bonds in the amount of $20,000 to be used for park improvements and purchase of land. The acquisition of the land was taken for transferring the land to the State on October 25, 1935, and became Mill Creek State Park. The lake got its name because of mills along the stream. It was known as Mill Creek.

In December of 1935, a small group of W.P.A. men were sent to do some work. In the spring of 1937, barracks were erected to accommodate 300 men, who arrived and the building of the dam actually began. On the 20th day of December, the gates were closed and water began to rise. On the 2nd of February, 1938, the first splash of water spilled over the spillway. The flow of water from the springs would fill the basin in forty-four days. The dedication ceremonies of the lake were held October 1, 1938.

In 1937 Harry Imweihe was appointed caretaker, followed by his son, Harry, and then passed on to his son, Dan. Jack Mau was appointed executive officer and took command for a number of years. Darwin Koenig was also a caretaker after Jack.

On April 29, 1947, a flash flood damaged the dam. Surging waters skirted side walls and washed away the foundation of the spillway. Investigation started immediately for repairing the dam and on the 19th of June, work was started and by July 24th, swimming classes were begun. In June, 1959, the spillway was rebuilt and the dam was raised. The new spillway was completed on October 29, 1959. The lake proper covers 52 acres of ground and is 18(?) feet deep at its greatest depth.

The building of the dam was followed by the erection of the lodge. A management agreement was entered between the State Conservation Commission and the Board of Supervisors of O'Brien County on March 17, 1975 to become the O'Brien County Park. After the O'Brien County Conservation Board took over the park a contract in 1978 with NITC (Northwest Iowa Technical College now know as Northwest Iowa Community College at Sheldon, Iowa) to clean as much of the lake bed as possible and to dig a diversion channel around the back of the lake to prevent further buildup of silt.

Boy Scout Island was made in 1978, and is for the use of area Boy Scouts, though it may be used for other activities as well.

On the 4th of July, 1946, Paullina put on the first fireworks and celebration at the lake. Frank Briggie and Milton Ehlers headed a group of men setting off the display. These Fouth of July celebrations continued until the mid-1960's. 2016 is the fourth year there will be fireworks at the lake again.

Memorials of benches, picnic tables, shelters, and play gound equipment, have been donated in memory of:
Rex Barnes
Dennis J. Beltman
Allen Busch
Weber Clayton
J.D. Coldren
Lee E. Ewoldt
Marcella L. Ewoldt
Russ and Jean Hagenbucher
Terry Hatterman
Wayne Herwig
LeRoy and Helen Holck
Carroll and Irene Kuehn
Annabelle Leitz
Bob Leitz
Jack Mau
Norman F. and Nellie Meyer
Amber Mosier
Sherrie Nelson
Francis and Bonnie Pauling
Gloria Peuse
Terry Puhrmann
V. P. Riedemann
Chris Scuknecht
Travis Snyder
Russell Steinbeck
John and Marilyn Strack
Herbert Stugelmeier
Victor and Karl Swanson
Van and Ardeth VanBuskirk
Marvin Waite
James D. Wester
Mick and Martha Wood

And by these organizations:
Jaycee-ettes and Jaycees
Lutheran Brotherhood
Paullina Home Group
Paullina Women's Study Grooup

Edited from The Paullina Times May 12, 2016
Used with Permission from Marlo Ebel