and Don Valley Paper Mill Company. Immediately to the north of it was Bate Chemical and Polyresins Inc., manufacturer of oil- and water-based paint resins and adhesives. (It was also subcontracted from Lever Bros to make Ajax Liquid cleaners.) They operated until the late 1980s when they closed. Subsequently, the TRCA purchased the land and demolished all of the buildings except for Bate Chemical's research and development lab building. It was converted into the Toronto Police dog training facility. The rest of the area was cleaned up and the contaminated soil removed. On the north side of the valley, the land where a former brick making operation called Sun Valley Ltd. was used as an industrial landfill. This was used mostly for brick and ash waste from nearby industry. It was shut down in the 1980s. The dump was capped with clean fill and now is marked by a large meadow covered with invasive grasses and plants. It is currently undergoing natural restoration efforts. In particular it has become the Don Valley site for Trees Across Toronto, a citywide tree planting program. Forest Crothers Woods is known as a beech-maple-oak climax forest. It includes such tree species as American beech, sugar maple, black walnut, and red and white oak. There are also a few butternut which are currently listed as an endangered species by the Species at Risk Act. In, 1995, the forest was designated as an ESA partly due to the quality of the forest but also to the presence of rare understory plants. These include greater straw sedge, thin-leaved sunflower, and pale-leaved sunflower. The forest is a good place to view common spring ephemerals such as trout lily, trillium, and bloodroot. Animals typical of an urban forest can be seen here. Black-crowned night herons have been spotted near the river and at ponds within Crothers Woods. red-tailed hawks are also frequent visitors and can be seen hovering over the woods. Recently white-tailed deer have been spotted in the woods and it appears they are becoming permanent residents. Mountain biking Due to the steep walls and the extensive gullies that exist through this part of the valley, Crothers Woods attracted the attention of many user groups over the years. A trail network which was begun by motorcyclists in the 1960s was subsequently adopted by cyclists in the 1980s with the advent of the mountain bike. Cycling usage grew steadily