The Russian 'power ministries', of which the Federal Penal Service is one, remain secretive and suspicious of scholars showing an interest in their activities, so there are inevitably severe problems accessing the data needed to map Russia's changing penal geography.
The sources of data used to create the maps on this site are diverse, and our strategy of piecing together a patchwork of data reflects the difficulty of obtaining information about the Soviet and Russian penal systems. We draw upon official data where this is available, data collated by prisoner support groups, and information published by human rights NGOs. The sources of data and the methodologies employed varied between the Soviet and the post-Soviet period.
We are aware that the statistics for camp populations are very controversial and have been the subject of intense academic debate. Data for the early Soviet period, specifically 1929-1960, are available courtesy of the non-governmental organisation 'Memorial' which has traced the location of hundreds of penal institutions and collated prisoner numbers for each institution where these exist. No data are publicly available for the period after 1960 to the collapse of the USSR.
In addition to published materials, Russian historians working in central and regional archives have provided data that have allowed us to map the distribution of the gulag at spatial scales below the level of the USSR and Russian republic. Dr Andrei Suslov provided the materials that form the basis of the maps of special settlements in Perm' krai. These data are very rich so that in addition to mapping the distribution of the command centres for special settlements, they have allowed us to make maps relating to the principal employments of the 'contingent' in special settlements, the total population of special settlers and to identify clusters of settlements.
We faced a number of technical challenges in mapping the Memorial data for 1929-1960.
First, we wanted to know where prisoners were and when, but tracing them was problematic. The Gulag was a fluid organisation; institutions, by which we mean prisons, camps, and prisoner settlements, changed both their names and locations over time, for a variety of reasons. The precise place in which prisoners and special settlers were confined was frequently different from the site of the camp 'administration', especially where prisoner labour was mobile rather than sedentary (eg building a railroad). In many cases, Memorial has traced the exact location of institutions, and we have used these data where they exist. In some cases just the raion, the smallest level of spatial administration division, is known, but not the exact location of the institution. In these cases we have used the raion centre as a proxy.
Second, although prisoner censuses were taken fairly frequently between 1929 and 1960, the same census dates were not used for all institutions. This meant that taking 'snapshots' on specific dates was problematic, and risked vastly underestimating prisoner numbers. We tackled this problem by treating location of institutions and prisoner number as two separate datasets. By using Memorial's prisoner number data we established the 'lifespan' of particular institutions - the periods for which they were operational, and mapped the location of these institutions on 'point maps', over two-yearly intervals, to show the geographical expansion and contraction of the Gulag.
Using the Memorial archive data, we have produced for each camp a 1-year average number of prisoners. If for example, there were figures for a particular camp every year for a five-year period, we would sum and divide by 5. If there was only one year's population, we would take that one. If there were two years, we would sum and divide by 2. We would then sum the average for each camp that we had to achieve an approximate overall total. This is very approximate - we are deriving a hypothetical average, because it does not relate accurately to any particular year. The year groups have been chosen in order to make sure that we have some prisoner population figures for every camp in the USSR.
Finally, since Memorial's data is for the entire Soviet Union, we have mapped the Gulag in its entirety. However, we have also generated a series of maps of the Russian Soviet Socialist Republic, precursor to the Russian Federation, in order to facilitate comparison with our contemporary maps from the period post-1991.