The course of Plum Creek flows north-east past the
Souris Sand Hills then back east-southeast towards the Souris River in a gentle arc. While Plum Creek itself is relatively short with no notable tributaries along its course, it has a large
drainage basin that goes as far west and north as
Grenfell, Saskatchewan. The source for Plum Creek is Plum Lakes. The inflows for the Plum Lakes, which are a group of lakes to the south and east of
Oak Lake, include Maple Lake (fed by Stony Creek), Bell Creek, and Oak Lake. Oak Lake, through Oak Lake Dam (49°38′27″N, 100°45′8″W), is the primary inflow for the Plum Lakes. Along the western side of Oak Lake is Oak Lake Marsh, which is where Oak Lake's primary inflow,
Pipestone Creek, enters the lake. With a basin size of , Pipestone Creek and its tributaries make up the bulk of the land area in Plum Creek's overall watershed. Pipestone Creek drains much of the northern and eastern portions of
Moose Mountain Upland in
Saskatchewan and as far north and west as Grenfell, Saskatchewan. Maple Lake, Plum Lakes,
Lauder Sand Hills, Oak Lake, Oak Lake Marsh (which is almost 4 times the size of Oak Lake itself), and Plum Creek are all part of
Important Bird Area (IBA) Canada called Oak Lake / Plum Lakes Area. This IBA is a very important breeding ground and stop-over for migrating birds and it covers of habitat. ==Concrete Bowstring Arch Bridge No. 734==