How far away from Winnipeg is Oak Marsh?
I believe it is about a 15 min. drive north of Wpg., eagle. Not very far. I have taken my Kinderchicklets there for a field trip, in years gone by. It is an amazing place to visit! 
Oak Hammock Marsh is about a one hour drive from the Radisson Hotel, but only about a 5-10 minute flight for the birds (straight line). It's north of the City, about 20 minutes from the City limits and is the last remnant of the old St Andrews Bog.
It's a RAMSAR designated site .... that is the Convention on Wetlands of International Importance especially as Waterfowl Habitat (Ramsar Convention) was adopted in Ramsar, Iran, in 1971, and came into force in 1975. The Convention's mission is the conservation and wise use of wetlands by national action and international cooperation as a means of achieving sustainable development throughout the world.
The site comprises 1,400 ha of marsh and 2,200 ha of upland. The marsh is a remnant of a 47,000 ha marsh located in the former prairie north of Winnipeg. This larger marsh known as St. Andrews Bog, underwent drainage for agricultural purposes beginning in 1897. By the early 1960s, all but 250 ha had been drained. Measures to restore a portion of the bog began in 1967 when the Governments of Manitoba and Canada embarked on a cooperative program with Ducks Unlimited Canada and wildlife conservation organizations. By 1974, 3,450 ha of marshland and marginal agricultural land had been purchased and 22 km of dykes built to trap and hold water in three separate compartments. In addition, 58 nesting islands were constructed within the three compartments. In 1984, Manitoba signed a development agreement with Ducks Unlimited Canada to construct additional dykes, creating a fourth cell, control structures, nesting islands and water supply works. (source: Govt of Canada)For more check out the
History of OHM . As for its name check out
Genesis of Oak Hammock - its a nice story, true or not! Here's some information on the centre along with a map -
Oak Hammock Marsh Interpretive Centre .
Oak Hammock Marsh is one of Manitoba's top birding destinations and is recognized as a globally significant IBA based upon number of Short-billed Dowitchers, Hudsonian Godwits and staging geese. A total of 296 species have been recorded in this relatively small area. Up to 5,500 pairs of breeding Franklin’s Gulls have been recorded, representing at least 1.6% of the North American populations. As many as 70 pairs of Black-crowned Night-Herons, which represents approximately 1.4% of the Canadian population breeds at Oak Hammock Marsh. (source: IBA - Important Bird Areas of Canada)
