Mosquito Control & Treatment Map
Explore where and how LMCD monitors and treats mosquito breeding sites across Leavenworth and the lower Icicle Valley.
Treatment Zone Map
Five treatment zones cover the district. Use the checkboxes to show or hide zones and monitored hot spots. Select a shape or marker for details.
Map key
Reference
Treatment zones
Monitoring
View as a text list instead
Jump to the accessible zone & site table below the map.
District boundary and all 90 treatment site locations are sourced directly from the district's official GIS boundary export. The 5 treatment zones are illustrative geographic groupings within that real boundary, not separately surveyed sub-zone lines; contact the district office for parcel-level boundary questions.
Zones & treatment sites — text reference
A full text equivalent of the map above, for screen-reader users, printing, or anyone who prefers a list. District boundary and site locations are sourced from the district's official GIS export.
| Code | Zone name | Description | Treatment method |
|---|---|---|---|
| ZONE A | North of Highway 2 | Ski Hill, Alpine Heights & West Benton neighborhoods, including storm drains and residential ponds. 24 surveyed sites. | Bti briquettes, inspected monthly (Mar–Oct) |
| ZONE B | South of Hwy 2 / City Parks | Downtown river corridor including Waterfront Park and Blackbird Island. 22 surveyed sites. | Bti granules, biweekly in peak season |
| ZONE C | E. Leavenworth Rd (North Section) | East Leavenworth Road corridor nearer to town. 11 surveyed sites. | Bti briquettes, monthly inspection |
| ZONE D | E. Leavenworth Rd (Central–South) | East Leavenworth Road corridor further from town, toward the southern district boundary. 11 surveyed sites. | Spot treatment as scouting indicates |
| ZONE E | Icicle Rd & Side Roads | Icicle Road and side roads at the mouth of the lower Icicle Valley; site of the 2017 helicopter larvicide application (~20 acres). 22 surveyed sites. | Ground larvicide + occasional aerial Bti |
Treatment sites by zone (90 total)
Every surveyed site from the district's GIS export, grouped by zone. Coordinates are latitude, longitude.
ZONE A — North of Highway 2 (24 sites)
- Site 1047.6012, -120.6679
- Site 1247.5996, -120.6717
- Site 1347.6015, -120.6783
- Site 1447.6015, -120.6758
- Site 1547.6024, -120.6688
- Site 1647.6035, -120.669
- Site 1847.603, -120.6673
- Site 1947.6031, -120.6642
- Site 2147.6062, -120.6665
- Site 21b47.6079, -120.6729
- Site 21c47.608, -120.6726
- Site 2247.6125, -120.6678
- Site 23a47.6127, -120.659
- Site 23b47.6097, -120.658
- Site 23c47.6069, -120.659
- Site 2447.6056, -120.6586
- Site 2547.6062, -120.6568
- Site 2647.6052, -120.6546
- Site 2747.601, -120.6583
- Site 27a47.6052, -120.6581
- Site 27b47.601, -120.6553
- Site 2847.6102, -120.6504
- Site 28b47.605, -120.649
- Site 2947.603, -120.6505
ZONE B — South of Hwy 2 / City Parks (22 sites)
- Site 3147.5867, -120.6675
- Site 3247.5883, -120.6643
- Site 3347.5883, -120.6668
- Site 34b47.5926, -120.666
- Site 3547.5927, -120.664
- Site 4647.5908, -120.6612
- Site 4747.5877, -120.6615
- Site 4947.5865, -120.6602
- Site 5147.586, -120.6628
- Site 5247.5831, -120.6654
- Site 5447.5852, -120.6611
- Site 5847.5798, -120.661
- Site 6347.5759, -120.6608
- Site 6447.5741, -120.6635
- Site 6847.5722, -120.6602
- Site 72b47.5648, -120.6632
- Site 7347.5687, -120.6655
- Site 76a47.5631, -120.6639
- Site 76b47.5629, -120.6651
- Site 8247.5691, -120.6675
- Site 8347.5718, -120.663
- Site 84a47.5789, -120.6642
ZONE C — East Leavenworth Rd (North Section) (11 sites)
- Site 3647.5933, -120.6581
- Site 3747.5947, -120.6567
- Site 3847.5963, -120.6553
- Site 39c47.5941, -120.6549
- Site 4047.5978, -120.6501
- Site 41x47.5908, -120.6561
- Site 4147.5943, -120.6529
- Site 4247.5909, -120.6582
- Site 4347.5928, -120.6563
- Site 4447.5917, -120.6583
- Site 4547.5917, -120.66
ZONE D — East Leavenworth Rd (Central–South) (11 sites)
- Site 4847.5893, -120.6572
- Site 49.x47.5859, -120.6581
- Site 5547.5842, -120.6578
- Site 5647.5864, -120.6592
- Site 6047.5819, -120.6552
- Site 6147.5792, -120.6546
- Site 6247.5787, -120.6578
- Site 6547.575, -120.6555
- Site 66a47.5671, -120.6576
- Site 66b47.572, -120.6517
- Site 6747.5729, -120.6591
ZONE E — Icicle Rd & Side Roads (22 sites)
- Site 147.5914, -120.6742
- Site 347.5908, -120.6705
- Site 447.5949, -120.6734
- Site 547.5945, -120.678
- Site 1147.598, -120.6741
- Site 3047.5865, -120.6702
- Site 5347.5825, -120.6676
- Site 7447.5654, -120.6684
- Site 76c47.5602, -120.6676
- Site 76d47.5547, -120.6688
- Site 76f47.5537, -120.6708
- Site 76g47.5516, -120.6717
- Site 7847.5517, -120.6832
- Site 7947.5638, -120.6687
- Site 8047.565, -120.6765
- Site 80c47.5645, -120.6744
- Site 8147.5673, -120.6816
- Site 84b47.576, -120.6681
- Site 84c47.5744, -120.6727
- Site 85a47.5726, -120.6792
- Site 8647.5852, -120.675
- Site 8747.5778, -120.6697
Pesticides & Chemical Usage
Treatment season runs approximately March 9 through October 15. LMCD prioritizes larviciding over adulticiding — adulticides haven't been deployed since 2007.
| Product | Type | Use |
|---|---|---|
| Bacillus thuringiensis subsp. israelensis (Bti) | Larvicide | Primary product, most treatment sites |
| Bacillus sphaericus | Larvicide | Standing water with high organic content |
| Methoprene | Larvicide (IGR) | Growth regulator, longer-residual sites |
| Spinosad | Larvicide | Used as needed |
| Paraffinic mineral oil | Larvicide / pupicide | Surface film treatment |
Adulticides (if ever needed, June–Aug window): malathion, natural pyrethrins, PBO, permethrin, etofenprox, naled, prallethrin, resmethrin, sumithrin.
Have questions about a specific product? Contact the National Pesticide Information Center, or reach the Washington Dept. of Ecology's Aquatic Pesticides Permit Manager for permit #WAG992036.
2017 Helicopter Application
In difficult-to-access terrain along the Icicle Valley, two aviation companies applied Bti granules by helicopter across approximately 20 acres in April and May 2017 — the district's only aerial larvicide application to date.
No-Spray List
Ask to be added to the No-Spray List and we'll flag your property for the treatment team. This is not a guarantee of general non-treatment — larviciding of public breeding sites and mosquito-borne disease response may still occur nearby — but it lets our field staff know your preference.
- Confirmation by email or phone
- Renewed annually each spring
- Applies to your listed address only