These were found on the east side of the Kaulenbach (brook) and in the upper reaches of the Sesterbach within neighbouring Laubach's municipal limits.

Stony and even craggy land with little deep soil made for very hard work and scant harvests, which could not feed local families, which tended to be big.

Medical help was very uncommon through all this poverty and extraordinarily hard and dangerous work, leading to a life expectancy among adults of roughly 50 to 60 years and an infant mortality rate of 40% right up to the age of five.

Their descendants can still be recognized by their now Germanized French surnames, among which are Buschwa, Allar, Gorges, Lefev, Gilles and Regnier.

Some of the pits were in private ownership, although often 100 or more persons from one family were shareholders, which made for lasting poverty not only among the workers but sometimes even among the business owners.

Wages for this extremely hard work were quite low, and owners' profits from these enterprises were only slight owing to high transport costs; slates were hauled by horse as far as Klotten, where they were loaded onto boats on the Moselle.

By 1898, the Eifel Railway from Mayen to Gerolstein had been running for three years and the workload at the slate pits in Leienkaul became a bit lighter.

"Maria Schacht" built a tramway of its own in 1907 and 1908 leading to the railway tracks at the Masburger Wald (forest) and running behind the "Wolfsburg".

At the same time, the "Müllenbacher Dachschieferwerk" built a railway powered by a diesel engine, which transported slates out of the Kaulenbach valley and up the steep Kaulenberg.