On January 20, 1884 the Alexandria Branch of the Pennsylvania Railroad was opened between Georges Station (Donohoe) and the Alexandria Coal Company's mines at Crabtree. Most of this can still be seen today and a lower portion is part of a proposed trail at Twin Lakes Park. In 1901 the branch was extended from Crabtree to New Alexandria. Later the branch was extended to the mines at Andrico, north of New Alexandria. Many parts of this can still be seen as well. The entire length from Donohoe to Andrico was 9.7 miles. The section from Georges Station to Crabtree was 4.55 miles. I'm not able to find when it was abandoned but passenger service between Donohoe and Andrico was discontinued on 1/1/1926 and the areas near Loyalhanna Creek were being lost around 1942 for the Conemaugh Dam flood control project. The branch itself is still shown on the 1960 county map.
The Donohoe Mine and Coke Works at Greenwald, east of Crabtree opened around 1900 by the Donohoe Coal and Coke Company and operated until September 1923 when the mine was sealed by striking miners and never reopened. The coke works contained 180 ovens circa 1909 and produced a high grade foundry coke. There are nowhere near that many remaining out here today. I did find a small bank separated from the main bank. This was the only place I found an intact oven. I wouldn't have even found this if I didn't come across a huge puddle on the old railway that I needed to bypass. The rest of the ovens are in pretty bad shape with none of the fronts left.
Here's a couple photos I found from 1909 of the coke plant.
Donohoe Coke Plant