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Mystery Cache

A Boy's Bridge Cache

A cache by Lumpheimers Send Message to Owner Message this owner
Hidden : 4/12/2009
2.5 out of 5
2 out of 5

Size: Size: small (small)

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Geocache Description:

Posted coordinates are not actual cache coordinates. The posted coordinates mark the first stage of the offset puzzle where you need to collect some information to solve for the final coordinates.

Park on Foundry Street or in one of the Savage Mill lots. Suggested parking: N39 08.141 W076 49.502.

This is a short hike from the historic Bollman Truss Bridge along Savage Mill Trail. There is a wide, flat trail for the first three quarters of the walk which overlooks a scenic section of the Little Patuxent River. Final approach involves a short hill and some light bushwhacking.

This cache has been placed with the permission of the Howard County Department of Recreation and Parks and celebrates the Bollman Truss Bridge, whose superstructure incorporates the Bollman Suspension Truss configuration patented by Wendel A. Bollman (born 1814, died 1884).

The iron bridge was an economic solution to the high cost of masonry bridges and the limitations of wood, which could not support much weight and was susceptible to fire and rapid decay. The world's first iron bridge originated in Coalbrookdale, England, in 1779.

The final cache coordinates are N39 08.ABC W076 50.0DE

To solve, do some simple math using dates that appear at the top span of the bridge at the marked coordinates.

A = Last digit of the year in which the "Bollman truss" design was patented.

B = Using the four-digit "Renewed" date, subtract the third digit from the fourth digit.

C = Using the four-digit year in which this bridge was built, divide the first two digits of this year by the last digit.

DE = How many years between the signing/ratification of the Declaration of Independence in 1776 and the year in which this bridge type was patented?

A wide, well-maintained trail will take you to within about 500 feet of the cache. After that you'll have to follow a narrow trail up a short hill; the trail will lead you to within about 120 feet of the cache.

On warm summer days the initial part of the trail will be crowded.

You can check your answers to the offset puzzle at this link:
(visit link)

Additional Hints (Decrypt)

Ybt vg.

Decryption Key


(letter above equals below, and vice versa)



172 Logged Visits

Found it 146     Didn't find it 8     Write note 7     Temporarily Disable Listing 2     Enable Listing 2     Publish Listing 1     Owner Maintenance 5     Post Reviewer Note 1     

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**Warning! Spoilers may be included in the descriptions or links.

Current Time:
Last Updated: on 4/21/2018 8:47:37 AM Pacific Daylight Time (3:47 PM GMT)
Rendered From:Unknown
Coordinates are in the WGS84 datum

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