Lac La Croix Research Natural Area

[photo:] Lac La Croix RNA. Photo by Jack Greenlee, USDA Forest Service.

St. Louis
Upland boreal forests occupy most of the RNA. The distinguishing feature is the old-growth eatern white pine (Pinus strobus) and red pine (Pinus resinosa); one of the few remaining, largely unmodified tracts of high quality virgin pine in the Lake States.

Ecological Information

Physical and Climatic Conditions

Nearest weather station, with distance and direction from RNA:
Winton Power Plant is located 24 miles (38.4 km) south-southeast of the RNA.
Annual precipitation (type, seasonal distribution) :
Average annual precipitation is 27.5 inches (69.9 cm), with 11.4 inches (28.9 cm) falling in summer. Average annual snowfall is 43.7 inches (110.9 cm).
Maximum and minimum temperatures:
Maximum: 97 ºF, Minimum: -45 ºF
Annual: 27.4 ºF, 48.4 ºF
January: -7.4 ºF, 14.5 ºF
July: 55.7 ºF, 77.8 ºF.
Elevation ranges from 1200 to 1300 feet (392-425 m).
Geology and Soils:
The topography is rugged, with a number of tall granite cliffs. The soil is variable, ranging from shallow sandy loams to fairly deep glacial deposits of sand.
Aquatic Features:
Nearly ¼ of the site is covered by water. Boulder River transverses the site, and Lake Agnes and Boulder Bay border the site.

Ecological Classification & Inventory

Northern Superior Uplands (212L)
Border Lakes (212La)
Landtype Association:
Plant Communities:
SAF Cover Types (list acres) Kuchler Types (list acres):
1 Jackpine (28) 84 Great Lakes Spruce-fir Forest (36)
5 Balsam fir (36) 85 Conifer Bog (39)
12 Black spruce (39) 86 Great Lakes Pine Forest (682)
15 Red pine (208)  
16 Aspen (214)  
21 White pine (232)  

Complete Plant List

Common Mammal Species:
Moose (Alces alces), black bear (Ursus americanus), white-tailed deer (Odocoileus virginianus).

Related Reports and Publications

Aakala, T. S. Fraver, B.J. Palik, and A.W. D’Amato.  2012.  Spatially random mortality in old-growth red pine forests of northern Minnesota.  Can J For Res 42:  899-907.

Fraver, S. and B.J. Palik.  2012  Stand and cohort structures of old-growth Pinus resinosa-dominated forests of northern Minnesota, USA.  Journal of Vegetation Science 23:  249-259.

LeBarron, Russel K. and Clare Hendee. 1942. Establishment Record of the Keeley Creek and Lac La Croix Research Natural Areas within the Superior National Forest. Unpublished report on file at the Northern Research Station, Rhinelander, 26 pages.

Heinselman, Miron. 1996. The Boundary Waters Wilderness Ecosystem. University of Minnesota Press, Minneapolis, MN. 334 p.

Last Modified: August 19, 2021