1921 year – the first official statement from Prof. Władysław Szafer (the Chief of National Committee for Nature Protection) on the necessity for protecting the Pieniny Mountains.

14th March 1921 – Stanisław Drohojewski set up the nature reserve on the Zamkowa hill in Czorsztyn.

1922 – Prof. Stanisław Kulczyński worked out the project of creating "the Pieniny reserve" (16.5 km2).  According to the project, strict reserve was to cover the area of Three Crowns Massif and Pieninki, and the rest was planned to be under the partial protection.

10th September 1923 – a conference in Szczawnica on possibilities for purchasing the Pieniny properties from private owners.

6th May 1924 – As a result of signing up the protocol by Polish and Czechoslovakian Committee in Cracow, the country border was determined as well as approval of the programme for establishing transboundary nature and landscape parks.

2nd August 1926 – Ministry of State Treasury rejected the first project on forests purchase for the National Park.

8th November 1928 – approval of the next cost estimate and the Council of Ministers' Economic Committee Resolution on land purchase.

March 1929 – the Act of purchase by the State Treasury the most valuable part of Pieniny (Three Crown Massif stretching out to Pieniński stream) was signed.

31st May - 3rd June 1929 – a Commission worked on approval of the area that had been purchased and on drawing the Park's boundaries. Also some resolutions were passed that determined organization of the Park and tourist traffic.

July 1930 – 260 hectares of forests that covered the tops of Sokolica and Czertezik peaks (stretching out from the Pieniński Stream to the farmlands in Szczawnica and Krościenko) was purchased from the Krościenko owner - Zygmunt Dziewolski.

31st August 1930 – ceremony in Szczawnica, proclaiming the Pieniny National Park.

2nd August 1931 – during the conference held in Krościenko, representatives of National Council of Nature Protection, State Forest Authority and Polish Tourism Society approved the project on organization of the Park and marked tourist trails, defined the qualifications for the future Park's Director as well as determined the guidelines for Polish and Czechoslovakian co-operation.

24th September 1931 – a Polish-Czechoslovakian agreement on the Pieninska Road signed in the city of Gdynia. Since that day, the road has been opened only for tourism and local traffic and closed for motor traffic. At the same time motor boats on the Dunajec River were forbidden.

winter 1931 - spring 1932 – The Ministry of Agriculture and the Directorate of State Forests in Prague issued a directive on setting up a reserve called "Slovenski Prirodni Reservace in Pieniny" (covering 420 hectares), located on the former Czerwony Klasztor forest administration region.

23rd May 1932 – The Ministry of Agriculture signed up the directive on establishing the Pieniny National Park.

1st June 1932 – Establishing the National Park in the Pieniny. The Ministry directive was published in "Monitor Polski", Nr 123.

13th June 1932 – Engineer Tadeusz Owczarzak was nominated as manager of Pieniny National Park.

9th July 1932 - The Czechoslovakian Ministry of Agriculture signed up the directive on establishing the Slovak Nature Reserve in Pieniny.

12th July 1932 - Establishing the Slovak Nature Reserve in the Pieniny

17th July 1932 – a ceremony for proclaiming the first transboundary national park in Europe.

8-9th January 1934 – the first meeting of Polish Pieniny National Park's and Slovak Nature Reserve's representatives.