A good reference answers a particular question. A field guide may help explain an animal’s habitat; an agency page may describe an encounter response or a rule; a study may examine a narrow outcome under stated conditions. The annotations below say what each source covers so that the next step in reading is clear. They are descriptions of the references, rather than endorsements by the organizations named.
Start with Features by subject for the longer regional accounts, or use natural events calendar when timing is the question. The source’s own scope matters: Missouri observations are not automatically exact Illinois dates, and a study of a particular task is not a medical program.
Agencies and field guides
U.S. Forest Service’s Shawnee National Forest page describes the forest’s southern Illinois setting, oak-hickory woods, wetlands, canyons and bluffs.
Missouri Department of Conservation’s American-beaver guide describes identification, waterside habitats, bank dens and the seasonal foods of beavers in Missouri.
Wildlife Illinois’s beaver account discusses the animal’s identification, signs and habitat effects, including the wetlands its activity can create.
USA National Phenology Network’s introduction to phenology explains recurring life-cycle timing and how observations help researchers understand responses to environmental cues.
Illinois Department of Natural Resources’s iFish Illinois provides fishing-information sections covering water bodies, species, licenses and rules; seasonal notices require their own context.
Illinois State Climatologist’s Illinois climate discussion considers changing climate, severe weather and the uncertainties involved in linking particular hazards with broader trends.
Amphibians and reptiles
Missouri Department of Conservation’s cave-salamander guide describes the animal’s spotted appearance and its use of caves, rocky streams, springs and wooded settings.
Missouri Department of Conservation’s long-tailed and dark-sided salamander guide compares the forms’ coloration and distribution within Missouri rather than treating every striped salamander as identical.
Missouri Department of Conservation’s western-lesser-siren guide describes an aquatic salamander’s unusual limbs and gills, wetland habitat and nighttime feeding.
Missouri Department of Conservation’s snapping-turtle guide covers appearance, aquatic habitats, seasonal activity and the animal’s differing defensive behavior on land and in water.
Missouri Department of Conservation’s three-toed-box-turtle guide describes a land turtle’s shell, woodland and grassland use, food and seasonal movements.
Missouri Department of Conservation’s timber-rattlesnake guide describes rocky forest habitat, basking, seasonal activity and the need for immediate medical attention after a bite.
Illinois Department of Natural Resources’s Wildlife in the Classroom explains its non-endorsement of live-specimen collection and the rules and permits relevant to possessing wildlife.
Birds and mammals
Missouri Department of Conservation’s wild-turkey guide describes habitat for hens and young, changing seasonal foods, winter flocks and spring display behavior.
Audubon’s killdeer field guide describes open-ground nesting, the distraction display, feeding behavior and differences between resident and migrating populations.
Wildlife Illinois’s bobcat account describes coat, tail and tracks, and explains why a bobcat can be mistaken for a mountain lion.
Animal Diversity Web’s American-beaver account describes the beaver’s range and the structure of lodges, with explanations of how dams maintain surrounding water depth.
Audubon’s wild-turkey field guide describes a bird that travels on the ground, flies strongly and roosts in trees, alongside its habitat categories.
Cougars
Missouri Department of Conservation’s mountain-lion field guide compares the cat with a bobcat and discusses the physical evidence used to confirm a reported presence.
Wildlife Illinois’s mountain-lion account combines appearance and identification with agency guidance for keeping distance and responding to an encounter.
Outdoor Illinois Journal’s Illinois mountain-lion discussion places confirmed individual animals beside the species’ earlier elimination from the state.
KFVS12’s report of confirmed mountain-lion sightings describes the Illinois Department of Natural Resources confirmation in Jackson and Union counties.
Federal Register’s eastern-puma final rule records the U.S. Fish and Wildlife Service’s extinction determination and removal of that subspecies from the federal endangered-wildlife list.
National Park Service’s mountain-lion safety guidance explains why distance, an escape route and a response that avoids running matter in an encounter.
Plants and fungi
Missouri Department of Conservation’s morel field guide describes spring fruiting, woodland and river-bottom habitats, look-alikes and the cautions surrounding mushroom identification.
Wikipedia’s Gyromitra esculenta reference describes a false morel’s appearance and classification, alongside discussion of its toxicity and identification difficulties.
U.S. Forest Service’s ghost-pipe account explains the pale plant’s flowering period and its indirect relationship with trees through fungi.
Missouri Department of Conservation’s ghost-pipe guide describes the plant’s nodding flowers, Missouri flowering period and below-ground fungal connection to tree roots.
Wikipedia’s frost-flower reference explains ice ribbons extruded from stems and distinguishes the forms gathered under the frost-flower name.
Wikipedia’s common-dittany reference describes a native mint-family plant, its dry woodland setting, late-season blossoms and connection with frost flowers.
Wikipedia’s butterfly-gardening reference considers habitat for the butterfly life cycle and the importance of plants used by larvae as well as adults.
Sky, calendar and folklore
Wikipedia’s almanac reference explains how calendar-organized publications combine practical subjects and astronomical information for different readerships.
NASA’s moon-phase explanation shows how the visible sunlit portion changes through the lunar cycle and explains the named phases.
Wikipedia’s full-moon reference discusses the phase itself and the traditional harvest and hunter’s moon names, keeping astronomy beside cultural usage.
Wikipedia’s equinox reference explains the Sun’s apparent crossing of the equator and why daylight and darkness are only approximately equal.
Wikipedia’s solstice reference describes the limits of the Sun’s seasonal path and the associated longest and shortest daylight periods.
Wikipedia’s meteor-shower reference explains radiant points and debris streams, then lists established showers with broad seasonal timing.
Wikipedia’s weather-lore reference considers informal forecasting traditions and the atmospheric circumstances behind some familiar sayings.
Wikipedia’s will-o’-the-wisp reference describes the marsh-light tradition and distinguishes its folkloric interpretations from proposed natural explanations.
Gardening
University of Illinois Extension’s home-vegetable-gardening material brings planning, soil, crop timing, watering and pest management together as parts of garden work.
USDA’s Plant Hardiness Zone Map explains the winter-temperature basis used to judge where perennial plants are likely to thrive.
University of Illinois Extension’s lawn-grub guidance distinguishes beetle larvae and their root feeding from other possible causes of brown lawn patches.
University of Illinois Extension’s explanation of mole diet states why reducing lawn grubs is unlikely to remove a mole problem when earthworms remain an important food.
Wikipedia’s milky-spore-disease reference describes the soil bacterium and its disease relationship with Japanese-beetle grubs, a biological subject rather than a brand recommendation.
University of Illinois Extension’s lunar-influence discussion reports an Agronomy review of proposed lunar effects on plants and the absence of a consistent supporting relationship.
NC State Extension’s gardening-by-signs discussion describes fruitful and barren zodiac classifications as beliefs and considers their relationship with the evidence.
History and archaeology
Wikipedia’s Anna Pottery reference describes the regional pottery, its founders and the museum collections holding examples of its work.
Krannert Art Museum’s Anna Pottery snake-jug discussion considers the object’s figural decoration and changing scholarly interpretations of this kind of pottery.
Wikipedia’s Fountain Bluff reference describes a Mississippi-floodplain hill range, its sandstone cliffs, geological setting, plants and rock-art context.
Wikipedia’s Piney Creek Ravine reference identifies the Illinois natural area and its cliff-face rock art, giving context rather than an access itinerary.
Wikipedia’s Cahokia reference describes the Mississippian urban center and distinguishes its inhabitants from the later people whose name the site carries.
Wikipedia’s Cahokia Woodhenge reference describes timber circles and the archaeological evidence considered in interpreting them as seasonal solar markers.
Wikipedia’s archaeoastronomy reference explains an interdisciplinary study of past sky knowledge and the difficulty of combining different kinds of evidence.
Health outdoors
Office of Disease Prevention and Health Promotion’s physical-activity-guidelines page introduces the federal guidance and related educational resources without replacing individual medical advice.
MedlinePlus’s heat-illness information describes heat-related conditions, warning signs and the added concern posed by hot, humid outdoor conditions.
MedlinePlus’s tick-bite information explains ticks, possible tickborne disease and the outdoor settings in which contact can occur.
Illinois Department of Public Health’s Lyme-disease account describes transmission by infected blacklegged ticks and the presence of infected ticks in Illinois.
MedlinePlus’s poison-ivy, oak and sumac information describes plant-oil contact, the resulting rash and the ways oil can remain on clothing or other surfaces.
PubMed’s record of a downhill knee-force study describes a comparison of walking with and without hiking poles and the knee-related measurements examined.
PubMed’s record of a downhill-walking study with packs describes pole use, different carried loads and the lower-limb joint measurements examined under those conditions.
For the regional distinction between records, species questions and agency advice, continue to Cougar questions answered. Walking the hills brings the outdoor-health references together with their research limits. No general reading list replaces medical care or the current rules of the relevant authority.