Ticket D: Fog sites and drone airspace around Grayslake, IL (Lake County)

Prepared 2026-10-16. Reference: Grayslake village centre 42.3447, -88.0418 (ticket). Drive times are OSRM public-router estimates, not measurements. Sunrise is about 7:08-7:15 am CDT on Oct 19-25 (my NOAA-formula estimate, +/-2 min); clocks fall back Nov 1. Airspace is a data lookup, not a legal determination; confirm at the launch point in B4UFLY or Aloft.

Where the ticket and the evidence disagree

1. Brae Loch is a Lake County Forest Preserves (LCFP) course. The ticket said so and the course site confirms it. It is therefore "District Property", and LCFP's drone-permit rule applies in addition to any owner consent. I do not know which course is the client's, so all are carried.

2. Countryside is LCFP, not private, and 23.6 min away. Excluded with ThunderHawk (26 min), Deerpath (24.5) and Shepherd's Crook (33) under the ~15 min rule. Stonewall Orchard (18 min) is kept only for its Grayslake 60030 address.

3. KUGN's Class D is a 4.0 nm circle in the FAA data, not ~4.3 nm.

4. Great Lakes Naval Station is not on the FAA's published national-security list (see Airspace).

5. Prairie Wolf Slough is 30 min away (Chain O'Lakes 29.6 min), outside the 20 min target. Chain O'Lakes is kept because hours were requested; Prairie Wolf Slough is not in the JSON because I could not verify its agency.

Summary table

Golf courses first, then public spots. "None found" means no rule on the pages reached, not a permission.

Relief (USGS 3DEP, site vs 1.5 km ring, ft): Almond Marsh 736 vs 715-810 (low basin); Heather Ridge 685 vs 654-753; Merit 695 vs 656-763; Hickory Knoll 829 vs 738-811 (above its surroundings).

Evidence

Coordinates. Nominatim name search, except Pine Meadow and Ivanhoe (name search failed; Nominatim lookup of way 196052494 and relation 15342412) and Volo Bog/Chain O'Lakes (IDNR page latitude/longitude). Grayslake Golf Course is not mapped in OSM: its coordinate geocodes the street, and two directory sites place it 0.25 km north. Forest-preserve coordinates are polygon centroids, not entrances.

Golf ownership (own pages). Bittersweet: "owned by the Village of Gurnee" (bittersweetgolf.com). Renwood: "operated by the Round Lake Area Park District" (renwoodgolf.com). Grayslake: "operated by the Grayslake Community Park District" (grayslakegolfcourse.com). Ivanhoe: "private golf club" (ivanhoeclub.com). Merit: "A Golf-Only Club" (meritclub.org). Brae Loch header: "Lake County Forest Preserves" (braelochgolfclub.org). Steeple Chase is listed as a facility of Mundelein Park & Recreation District (mundeleinparks.org/steeple-chase-golf-club). Village Green and HeatherRidge status rests on search-summary directory listings; heatherridgegolf.com served an unrelated spam page. Hickory Knoll: "hilly terrain", "water hazards don't come into play". Stonewall: "rolling hills, tranquil wetlands".

Hours. No golf course page reached states opening hours.

• LCFP preserves: "Hours: 6:30 am-sunset, daily." (Rollins Savanna, Almond Marsh, Grant Woods; Wayback copies of lcfpd.org pages, 2025). Opens about 40 minutes before sunrise.
• Volo Bog (IDNR about page): "Gates open at 8:00 am 363 days a year". About an hour after sunrise.
• Chain O'Lakes (IDNR): "Summer hours 6:00 a.m. to 9:00 p.m. Winter hours: 8:00 a.m. to sunset. Summer hours take effect April 1st and terminate the last weekend in October when hunting begins and the entire park is closed for hunting." Whether "last weekend" means Oct 24-25 or Oct 31-Nov 1 decides if next week is open.

Drone rules.

• LCFP, Regulations Governing the General Use of District Property (approved Jan 14 2020, amended Jan 17 2024), Sec. III.A: "No person shall use District Property for any of the following uses, unless the person has first obtained, and has physical possession of, a Permit allowing such use"; (v) "use of any fuel-powered, air-propulsion, electric powered, radio-controlled, or cellular-controlled unmanned aerial Vehicle (commonly referred to as a 'drone')"; (xx) "taking any still or motion pictures ... for commercial purposes". LCFP's fee ordinance has a Commercial Photography, Film or Video Permit. Source: https://www.lcfpd.org/file.aspx?DocumentId=9028 (read via Wayback copy dated 2024-02-25). A 2014 memo, seen only as a search excerpt, says drones may not launch or land outside the Van Patten Woods field. No drone-specific permit procedure found.
• IDNR, 17 Ill. Adm. Code 110.160(i): "Except in cases of emergency, for any person to land or attempt to land any aircraft on Department-owned, -leased or -managed property without prior authorization for each landing or attempted landing from the Department." (verified at ilga.gov). It says "aircraft", not "drone".
• Village and park-district courses: no rule found (620 ILCS 5/42.1(b-5), per ticket C, lets them adopt one).

Fog features (quotes). Rollins: "winds through wetlands, groves of large oaks and open prairies" (LCFP). Almond: "wetlands, oak woodlands, savanna, and old fields" (INPC). Grant Woods: "woodlands, prairie and marsh", "a tamarack bog" (LCFP). Volo Bog: "a floating mat of sphagnum moss, cattails, and sedges surrounding the open water" (IDNR). Chain O'Lakes: "6,500 acres of water and 488 miles of shoreline" (IDNR). Lakewood: search excerpts only.

AIRSPACE

Query. FAA ArcGIS (services6.arcgis.com/ssFJjBXIUyZDrSYZ): Class_Airspace/FeatureServer/0/query and FAA_UAS_FacilityMap_Data/FeatureServer/0/query, point-in-polygon at each coordinate, run 2026-10-16. Also bounding-box pulls of Class D/E2-E4 shapes and grid cells; the layers DoD_Mar_13 (FAA 99.7 list), Part_Time_National_Security_UAS_Flight_Restrictions, Prohibited_Areas, Special_Use_Airspace; the live TFR list (tfr.faa.gov/tfrapi/getTfrList, 75 entries); AirNav.

Grayslake village centre (42.3447, -88.0418), terrain 786 ft. It returned:

• Chicago Class B, floor 3,600 ft MSL (about 2,800 ft above ground).
• Chicago Class E5, floor 700 ft AGL; Illinois Class E5, floor 1,200 ft AGL.
• The O'Hare Mode C layer (surface to 10,000 ft MSL). Centre is 22.9 nm from ORD. 14 CFR 91.215(b)(2) sets the 30 nm rule, and 91.1(f) says Part 91 "does not apply to any aircraft governed by part 107" except listed sections. So it does not restrict Part 107 flights.
• No Class D or E2 surface area (KUGN's Class D edge is 5.0 nm away; KUGN reference point 9.0 nm). No UAS Facility Map grid (nearest KUGN grid 4.7 nm, ceiling 400 ft).
• Surface is Class G: LAANC not needed at 400 ft AGL or below.

Every other point returned the same stack (Class B floor 3,600 ft MSL). Differences: Hickory Knoll, Volo Bog and Grant Woods have no Class B shelf; Chain O'Lakes also lacks Mode C (32 nm from ORD). None is inside a Class D, E2 or grid cell.

Bittersweet, HeatherRidge and Merit are near the Class D edge and the courses are large: check the launch point. Distances are from the geocoded point (+/-0.3 nm).

• KUGN (Waukegan National, 42.4221, -87.8679). Class D is a 4.0 nm circle, surface to 3,200 ft MSL, with a Class E2 surface area of the same footprint. Tower 120.05, "[0600-2000]" (AirNav). The FAA data says "Legal description references NOTAM" for hours. No Class E3/E4 extensions in the data. Nothing here is inside it.
• Campbell Airport (C81, 42.3246, -88.0741). AirNav: Grayslake, "Open to the public", privately owned (Air Teck LLC), no tower. 1.9 nm from village centre. Surface is Class G under Class E5 (700 ft AGL). It has no UAS Facility Map record (zero grid cells list C81), so there is no LAANC. I found no authorization requirement, but it is a live strip: yield to traffic and pick launch points away from the approach ends.
• KPWK (Chicago Executive). Class D, surface to 3,000 ft MSL; edge 10.8 nm from village centre (reference point 15.1 nm). Tower 119.9 "[0600-2200 MON-FRI & 0700-2200 SAT-SUN]". Prairie Wolf Slough (excluded) is 1.0 nm from its edge. KENW (Kenosha) Class D edge is 11.7 nm away.
• Restrictions. Live TFR list: none in IL, WI or IN (only MI entries). The FAA 99.7 list has 15 Illinois entries (Scott AFB, RTC Joliet, MCC Chicago, Rock Island Arsenal, prisons, ANG bases) and none in Lake County; no features in the Lake County box in the part-time, prohibited-area or special-use layers. Great Lakes Naval Station (about 9 nm from the village centre, Nominatim centroid) is not on the list. The layer mirrors FAA's list; the authoritative source is the FAA UAS Data Display System, which I did not open.

LAKE INFLUENCE

No authoritative page found that quantifies autumn lake-breeze or lake-effect fog in Lake County. The closest sources:

• CIMSS (UW-Madison), 5 June 2019: "The arrival of lake breeze fog also restricted the visibility to 0.5 mile or less at Waukegan in northeastern Illinois." https://cimss.ssec.wisc.edu/satellite-blog/archives/33428 (a warm-season case).
• CIMSS, 15 May 2025: "As the wind shifts to easterly flow, it brings a shallow layer of cold air ashore. This cold air is much more stable than the air it is replacing, and is often less moist too even though it originated over a vast lake." https://cimss.ssec.wisc.edu/satellite-blog/archives/64814 (spring).
• Midwestern Regional Climate Center: "Dense fog is most prevalent in the Midwest from October through March in the hours between midnight and mid-morning." and "Cool air tends to pool in valleys or lower elevations in the terrain causing fog to be denser in these locations." https://mrcc.purdue.edu/living_wx/fog
• NOAA repository, Lake Erie south shore (analogue, not Michigan): "fog most commonly occurs when long clear nights encourage cooling of the air near the ground--an especially frequent situation in the fall. Since the lake water is comparatively warm in the fall, it often works to short circuit fog development." (OCR text.) https://repository.library.noaa.gov/view/noaa/7127/noaa_7127_DS1.pdf

Reading: lake-breeze air is cool and stable and can bring fog ashore in spring and summer; in autumn a relatively warm lake may suppress radiation fog nearby. Treat any lake term as a hypothesis for the backtest.

Weather infrastructure (fetched 2026-10-16)

• aviationweather.gov METAR API returned KUGN (04:51Z, 10 SM, BKN013 OVC023, 14/13), KPWK and KENW. KUGN station is 9.3 nm from village centre, KPWK 14.8, KENW 15.7.
• USGS 05528000 Des Plaines River near Gurnee (42.3439, -87.9411; 4.5 nm east): returned discharge 158 ft3/s and gage height 3.11 ft; no water-temperature series in the response.
• USGS 05549500 Fox River near McHenry (42.3100, -88.2515; 9.5 nm west): returned water temperature 18.0 C and gage height 4.01 ft; no discharge series in the response. USGS stamps these times with a -06:00 offset in October, which is not Chicago's current CDT offset; the tool should convert to UTC.

Could not verify

• Which course the client owns (all 12 are carried), and any golf-course hours or drone rule.
• LCFP: lcfpd.org returns a Cloudflare 403 (scripted and WebFetch). I used Wayback copies; Lakewood's page was not in the archive, so its hours and features rest on search excerpts. The live ordinance may differ from the 2024 copy.
• A drone-permit procedure at LCFP (none found), and LCFP hunting closures.
• Agency, access and any rule for Third, Gages and Fourth Lake shores; Prairie Wolf Slough agency and hours.
• The FAA UAS Data Display System, and a Great Lakes Naval Station restriction beyond the mirrored list.
• Village Green and HeatherRidge official sites (villagegreencc.com failed to connect; heatherridgegolf.com is spam).
• Fetch failures: lcfpd.org pages and file.aspx documents (403); repository.library.noaa.gov (403 to curl, opened via WebFetch); grayslakeparks.org/.com (no connection); mundeleinparks.org/golf/steeple-chase-golf-club.asp (404).

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