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Home , Bluegrass region, Geology of Kentucky, Kentucky Bourbon Trail, Woodford Reserve

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The Geological Society of America Field Guide 27 2012

Bourbon and springs in the Inner Bluegrass region of

Ashley M. Barton Cory W. Black Eagle Alan E. Fryar Department of Earth and Environmental Sciences, University of Kentucky, 101 Slone Building, Lexington, Kentucky 40506-0053, USA

ABSTRACT

This fi eld trip explores the role of geology in the origins and production of a dis- tinctly American distilled spirit. originated in the late 1700s and early 1800s in the Bluegrass region of north-central Kentucky. The Inner Bluegrass is marked by fertile, residual soils developed on karstifi ed . Corn was grown, ground, fermented, and distilled to yield a high-value product that would not spoil. The chemistry of water (dilute calcium-bicarbonate type with near-neutral pH) limits dissolved iron and promotes fermentation. Many farms and settlements were located near perennial springs, whose relatively cool tempera- tures (~13–15 °C) facilitated condensation of steam during distillation. We will visit three historically signifi cant springs. Royal Spring in Georgetown was an early site of whiskey production and is one of the few springs in Kentucky still used for municipal water supply. McConnell Springs was the purported site of Lexington’s founding and occupies a window in which distilleries once operated. Cove Spring in Frank- fort was the site of the fi rst public water supply west of the Allegheny Mountains. We will also tour two distilleries: (among the oldest and smallest in the state, and a National Historic Landmark) and (listed on the National Register of Historic Places).

INTRODUCTION the geologic and hydrologic setting of the Inner Bluegrass and the history of bourbon production. A case study illustrates how Karst terrain, which is formed by the dissolution of soluble the stable isotope oxygen-18 differs among various bourbons bedrock (primarily limestone), is characterized by sinkholes, and how bourbon becomes systematically enriched in the isotope sinking streams, caves, and springs. Approximately 15% of the during aging. Finally, we summarize each fi eld-trip stop. contiguous United States (Aley, 1984) and 55% of Kentucky (Currens, 2002) are underlain by soluble rocks. Many communi- ties in karst terrain formed around springs, which provided water for various purposes, including potable use, milling, and cooling. The Bluegrass region of Kentucky (Fig. 1) is bounded to These uses were integral in the development of bourbon whis- the west and south by the Plateau, to the north by key in the Bluegrass region of Kentucky. This chapter reviews the River, and to the east by the Eastern Kentucky Coal

Barton, A.M., Black Eagle, C.W., and Fryar, A.E., 2012, Bourbon and springs in the Inner Bluegrass region of Kentucky, in Sandy, M.R., and Goldman, D., eds., On and around the Arch and Niagara Escarpment: Geological fi eld trips in Ohio and Kentucky for the GSA North-Central Section Meeting, Dayton, Ohio, 2012: Geological Society of America Field Guide 27, p. 19–31, doi:10.1130/2012.0027(02). For permission to copy, contact [email protected]. ©2012 The Geological Society of America. All rights reserved.

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20 Barton et al.

Field of the Appalachian basin. The Inner Bluegrass is defi ned est elevations, at ~1100 ft (330 m) above sea level (asl), occur as the 30% of the Bluegrass region that is underlain by the rela- in the central portion of the area. The lowest elevations, which tively fl at-lying (McFarlan, 1943), which is occur along the in the southern and western Upper Ordovician in age (Clepper, 2011). The Inner Bluegrass is extremes of the area, range from 469 to 549 ft (143 to 167 m) separated from the Outer Bluegrass by the Bluegrass Hills, for- asl (McGrain and Currens, 1978). Locally, topography varies merly known as the Eden belt. Fertile, residual soils (e.g., according to the rock units exposed at or just below the surface. phosphatic silt loams) and numerous karst features have formed Topography formed on the Clays Ferry Formation consists of on the Lexington Limestone (Hendrickson and Krieger, 1964; narrow, steep-sided ridges with narrow, V-shaped valleys and McDonald et al., 1983; Newell, 1986). In the Inner Bluegrass, the dendritic drainage patterns. Thin limestone slabs cover steep Lexington Limestone rests on the underlying limestones of the slopes formed in in many places. In the lower part of High Bridge Group. Above the Lexington Limestone is the Clays the Clays Ferry Formation, more gently to moderately rolling Ferry Formation, which is composed of interbedded shales and uplands prevail, with small sinkholes and localized underground thin limestone layers. Table 1 shows the generalized stratigraphy drainage in the limestone units. The topography formed on the of the Lexington Limestone and subjacent and superjacent units. upper part of the Lexington Limestone consists of broad, fl at Most of the Inner Bluegrass consists of a gently rolling, valleys, while that formed on the lower part tends to consist of karst landscape dominated by fl uvial landforms. Relief is typi- rolling to dissected uplands. Sinkholes and well-developed sub- cally less than 160 ft (50 m) (Thrailkill et al., 1982). The high- surface drainage (solution conduits) are common. Bench-like

Figure 1. Inner Bluegrass region of Ken- tucky (from Paylor and Currens, 2002).

map area Kentucky fl d027-02 1st pgs page 21

Bourbon and springs in the Inner Bluegrass region of Kentucky 21 topography is formed on the more resistant shale, bentonite, and and a few meters above it. The Tyrone Formation is exposed in limestone layers along hillsides and valleys. the upper elevations of the cliffs and along the lower elevations The Kentucky River fl ows along the southern and western of tributaries. The upper few meters of the Tyrone and the over- edges of the Inner Bluegrass through a deep gorge known as the lying Curdsville Member of the Lexington Limestone form more Palisades, which represents incision by the river of ~330 ft (100 m) gentle slopes extending into the uplands. At least three levels of the below the adjacent land surface (Currens and Paylor, 2009). The Kentucky River have been identifi ed near its current location. An topography formed on the High Bridge Group typically consists age of ~1.5 million years for this stage of the river is suggested by of cliffs and steep slopes along the Kentucky River and its tributar- radiometric dating, whereas gravel deposits and terraces indicate ies. Numerous grikes (sub-vertical to vertical joints that have been both a relatively young stage of the river at the lowest levels of its enhanced by dissolution) occur within the walls of the gorge. The current valley, as well as an earlier, sub-upland stage of the river Oregon and Camp Nelson Formations only crop out at the river before incision into the plateau (Andrews, 2005).

TABLE 1. GENERALIZED STRATIGRAPHY OF THE LEXINGTON LIMESTONE SHOWING APPROXIMATE EQUIVALENCES WITH MAJOR LATE ORDOVICIAN CHRONOSTRATIGRAPHIC UNITS

Clays Ferry Formation

Upper Tongue of the Tanglewood Member Strodes Creek

Edenian Millersburg Member Millersburg Tongue of the Tanglewood Member discontinuity Devils Hollow Member Middle Tongue of Sulphur Well Member the Tanglewood Member Stamping Ground Member Lexington Limestone discontinuity Brannon Member Brannon Tongue of the Tanglewood Member Shermanian discontinuity

Perryville Member Lower Tongue of the Chatfieldian

Caradocian Tanglewood Member

Upper Ordovician Grier Member

Logana Member Kirkfeldian Curdsville Member

Rock Trenton-Maquoketa Unconformity landian

Tyrone Formation

Oregon Formation High Bridge Group Turinian Stage Camp Nelson Limestone Blackriverian Blackriverian

Note: F.R. Ettensohn, Department of Earth and Environmental Sciences, University of Kentucky, personal communication, 2011. fl d027-02 1st pgs page 22

22 Barton et al.

REGIONAL HYDROLOGY higher gradient. Flow directions in the groundwater basins often have little or no relationship to fl ow in the surface streams above. The majority of the Inner Bluegrass is drained by the Ken- The potentiometric surface in the Lexington Limestone is rep- tucky River and its tributaries. All surface drainage in the region is resented by the water surface in the larger conduits where fl ow ultimately confl uent with the . The climate is temperate, occurs under equilibrium conditions (Thrailkill, 1985). As such, with warm, humid summers, moderately cold winters, and no dis- it is very irregular in both lateral and vertical extent. tinct wet or dry seasons. The Kentucky River basin receives 46 in Although subsurface overfl ows between groundwater basins (117 cm) of precipitation on average annually, of which ~18 in are known to exist (Currens et al., 2002), interbasin subsurface (46 cm) contributes to surface water (Andrews, 2005). fl ow generally appears to be limited to small conduits in the epi- Surface and subsurface drainages are integrated through karst zone that are shallow and oriented parallel to land surface. sinkholes, conduit networks, and springs (Fig. 2). Dye-trace stud- Flow follows the topographic slope to emerge at small, high- ies by numerous workers in the Inner Bluegrass have delineated level springs that tend to be ephemeral. These interbasin areas groundwater drainage basins that discharge at springs, as mapped form part of the catchment areas for large springs draining the by Currens et al. (2002, 2003). These basins are typically <6 mi2 groundwater basins. Surface streams and high-level springs are (15 km2) in area, but can be as large as 25 mi2 (65 km2) (Thrailkill commonly perched on shaly and argillaceous facies within the et al., 1982; Currens et al., 2002, 2003). Dye-trace results sug- Millersburg and Brannon Members of the Lexington Limestone gest geologic control of the groundwater basins, with overall fl ow (Thrailkill et al., 1982). parallel to northwest-southeast oriented linear features and faults In the area of this fi eld trip, Carey and Stickney (2002, (Currens and Paylor, 2009). In the Inner Bluegrass, groundwater 2004a, 2004b, 2005a, 2005b) divided the Lexington Limestone basins have developed where fl ow in the reaches of former surface into upper and lower hydrostratigraphic units for the purpose of streams has been pirated by conduit development (C.J. Taylor, describing groundwater occurrence. The upper unit was defi ned U.S. Geological Survey, personal communication, 2011). to consist of the Strodes Creek, Millersburg, Tanglewood Lime- Thrailkill (1985) characterized fl ow in groundwater basins as stone, Devils Hollow, Stamping Ground, Sulphur Well, and Bran- dendritic because of the convergence of fl ow paths from recharge non Members. The lower unit included the Grier, Logana, and through swallets (openings in streambeds), sinkholes, and other Curdsville Members. It should be noted that this does not cor- locations. A single groundwater basin can underlie more than respond to the most current stratigraphic delineation of the Lex- one surface drainage basin, and the surface and subsurface basin ington Limestone as described in Clepper (2011) and depicted in shapes may have little relationship to each other. Conduits under- Table 1. In the upper unit, discharge rates can exceed 100 gallons lying the groundwater basins are nearly horizontal, have gradi- per min (gpm) (380 L/min) for some large springs and can be ents approximating those of the surface streams, and are almost 300 gpm (1100 L/min) from wells along large streams (Carey at the same level as the springs which drain them, although fl ow and Stickney, 2002, 2004a, 2004b, 2005a, 2005b). In the lower from the swallet recharging a conduit tends to have a much unit, discharge occurs to numerous springs, and wells can yield

Figure 2. Conceptual block diagram of Inner Bluegrass karst (not to scale) (Currens, 2001). fl d027-02 1st pgs page 23

Bourbon and springs in the Inner Bluegrass region of Kentucky 23 up to 150 gpm (570 L/min) along large streams (Carey and Stick- son, 1984; Crowgey, 2008). Small farmers began to supply grain ney, 2002, 2004a, 2004b, 2005a, 2005b). to larger distillers around 1800, and the range of proportions of In general, the quality of groundwater in the Bluegrass grains used in making bourbon was established by 1823 (Regan region depends on its geologic source and varies considerably and Regan, 2007; Crowgey, 2008). James Crow is credited with from place to place (Carey and Stickney, 2002, 2004a, 2004b, the standardization of bourbon production in the 1820s and 2005a, 2005b). Major-ion chemistry of shallow groundwater and 1830s, examining the science behind brewing and implementing streams originating in the Bluegrass region is a Ca-Mg-HCO3 use of thermometers, hydrometers, and saccharimeters (Allen, type with near-neutral pH, consistent with weathering of car- 1998; Murray, 1998). The mid-1800s brought about the use of a bonate rocks by meteoric recharge. Total dissolved solids (TDS) second distillation for purifi cation and increased ethanol content range from 200 to 400 mg/L for shallow groundwater and 100– (Pacult, 2003). 250 mg/L for streams (Hendrickson and Krieger, 1964). In the Besides the grains used and the aging process, the character Inner Bluegrass, groundwater tends to be hard to very hard; the of bourbon is often attributed to limestone water (Kroll, 1967; main constituents that negatively affect groundwater for domes- Carson, 1984; Murray, 1998; Pacult, 2003; Regan and Regan, tic use are chloride and hydrogen sulfi de. Saline water (defi ned 2007). Shallow groundwater and stream water in the Inner Blue- as TDS > 1000 mg/L) is typically found at depths >100 ft (30 m) grass contain suffi cient O2 to limit dissolved iron, an undesir- below principal valley bottoms in the fi eld-trip area (Carey and able constituent (Hendrickson and Krieger, 1964; Allen, 1998). Stickney, 2002, 2004a, 2004b, 2005a, 2005b). The pH of carbonate-buffered water also promotes fermentation (Willkie and Prochaska, 1943; Carson, 1984; Murray, 1998; BOURBON Pacult, 2003). In addition to the suitable chemistry of groundwa- ter, springs were historically desirable because their temperatures History of Bourbon (~13–15 °C) facilitated condensation of steam during distillation (Carson, 1984; Fryar, 2009). However, given the need for rela- The development of bourbon whiskey occurred after settlers tively large volumes of water in industrial-scale processes, the from the British Isles, who were experienced in distilling grain use of springs in bourbon production has waned (Fryar, 2009). spirits, encountered corn in eastern North America. The still was For example, Four Roses uses water from the Salt River; Ancient invented around 800–1000 CE (Pacult, 2003); distillation was Age and use water from the Kentucky River; and introduced to Europe by the 1100s and to the British Isles by Bernheim and use dechlorinated city water (Murray, the 1200s (Crowgey, 2008). Production of whiskey evolved in 1998). Nonetheless, some distilleries still rely on groundwater. northern Europe because the climate was conducive to the cul- Barton uses water from a spring and spring-fed lake; Maker’s tivation of grains but not grapes (i.e., making beer rather than Mark also uses a spring-fed lake; and Woodford Reserve uses wine) (Allen, 1998). Popularity of distilled beverages arose in water from an 80-ft (24-m) well (Murray, 1998). part because water was associated with disease (Murray, 1998). Even the process of charring the oak barrels for bourbon may Bourbon Production have begun as a way to sterilize the wood (Crowgey, 2008). One of the earliest records of a beverage made from fer- Certain criteria must be met in order for a beverage to be mented corn is that of George Thorpe in the Jamestown, Vir- considered bourbon. It must be distilled in the United States and ginia, settlement around 1622 (Carson, 1984; Regan and Regan, have a grain composition of at least 51% corn. The beverage can- 2007). Corn was harvested in what is now Kentucky starting ca. not be artifi cially altered (e.g., by special fi lters or additives), and 1774. Prior to 1778, settlers there could claim 400 acres (162 ha) it must be aged for at least 2 years in new, charred, white oak bar- of land if they would build a cabin and plant corn (Regan and rels. It cannot be distilled higher than 160 proof (80% alcohol) or Regan, 2007). As summarized by Fryar (2009), whiskey produc- put into barrels at higher than 125 proof (62.5% alcohol). Within tion emerged in various locations across the Bluegrass region in these strict guidelines, distillers create their own distinct fl avors the 1770s and 1780s. Rye was another grain used to make whis- by using different water sources, altering the proportion and type key; it grew readily and could be used as a cover crop or to feed of grains, using different yeast strains during fermentation, and/ livestock (Murray, 1998; Crowgey, 2008). Whiskey’s appeal was or aging their products for differing amounts of time. furthered by the fact that a farmer could earn more than 25 cents To begin making bourbon, corn, rye (or wheat), and malted per gallon (3.8 L) for whiskey on the frontier, as compared to a barley are ground to a fi ne powder and dissolved in water. The mere 10 cents for a bushel (35 L) of corn, which would yield 4– mixture is heated (commonly in a steam pressure cooker) to pro- 5 gallons (15–19 L) of whiskey (Kroll, 1967). duce sweet mash. After this has cooled, a portion of a previous From the 1790s to the 1830s, technological developments batch, known as , is added. Sugars in the mash feed and market forces led to the commercialization of whiskey pro- yeast, which produces CO2 and ethanol (C2H5OH). This fer- duction in Kentucky. The limited availability of rum, which was menting process typically takes 3 to 5 days. The fermented prod- distilled from sugar cane grown in the West Indies, gave corn uct, also known as brewer’s beer, is sent to a beer still, where and a market advantage in the United States (Car- steam creates an alcohol-rich vapor. This vapor is condensed to fl d027-02 1st pgs page 24

24 Barton et al.

create a low wine, which is passed through a second still to cre- Rayleigh fractionation, which can incorporate both equilibrium ate high wine (also known as white dog). High wine is placed and kinetic isotope effects. in new, charred, white oak barrels and put in a warehouse for a We examined fractionation of 18O in bourbon. It was hypoth- minimum of 2 years. During this time, the high wine migrates esized that products would become depleted in 18O during distil- into the walls of the charred oak barrel, picking up fl avors from lation, with high wine being isotopically lighter than low wine, the wood. Seasonal variations in temperature aid the migration and low wine being isotopically lighter than the source water. of the product in and out of the barrel. Water and some ethanol We also hypothesized that fi nal products would become progres- evaporate through the wood into the surrounding air (known as sively enriched in 18O during the aging process. Samples were the angels’ share). Loss of water through evaporation increases collected at various steps in the bourbon-making process from the proof of the product inside the barrel. After the appropriate three distilleries: Wild Turkey and Four Roses (both in Law- time frame, the master distiller will sample products and may renceburg, Kentucky) and (in Clermont, Kentucky). choose to mix, or marry, barrels to achieve a certain fl avor pro- These samples included tap/source water, low wine, high wine, fi le for the fi nal product. deionized water, steam, cut water, and fi nal products of vary- ing ages. Samples were taken to the University of Kentucky and Study of Stable Isotopes within Bourbon stored at 4 °C until analysis. In the stable isotope laboratory, exe- tainers were prepped by adding one to two drops of phosphoric

Atoms containing the same number of protons but differing acid before fl ushing with a 0.3% CO2/He mixture. Equilibration

numbers of neutrons are called isotopes. There are ~300 stable with CO2 was conducted after injection of 1 mL sample prior to and 1200 radiogenic isotopes. Stable isotopes have been used analysis on the isotope-ratio mass spectrometer. The δ18O value δ18 to examine a variety of natural processes, including paleocli- obtained for the CO2 gas was used as a proxy for the O value matology, elemental cycling (e.g., biomolecules within an eco- of the liquid sample. system), thermometry, and reaction mechanisms (Sharp, 2007). There was evidence of Rayleigh fractionation in both the Stable isotopes of hydrogen (2H) and oxygen (18O) can be used distillation and aging of bourbon. Figure 3 shows that δ18O val- to differentiate between waters from varying sources (Mook, ues decreased through the process from the source water to low 2006). Stable isotopes can also be used to evaluate food qual- wine to high wine. Source water values are similar to a sample of ity and origin, such as dilution of fruit juices or wine with water deionized Lexington tap water (−8.0‰ ± 0.1‰; C.S. Romanek, ( Monsallier-Bitea et al., 2006). Stable isotope abundances are commonly expressed in delta notation, which compares the rare isotope/common isotope ratio -4 in a sample (sa) to the same ratio in a standard (std). Typically, the rare isotope is heavier (i.e., contains more neutrons). For oxygen, -6 the international standard is Vienna Standard Mean Ocean Water 18 16 (VSMOW), which has an O/ O ratio of 0.0020052. Delta nota- -8 tion is measured in units of per mil (‰) and is calculated using the following formula: -10

18 Osa 16 -12 Osa δ18O(‰) = – 1 × 1000 (1) 18 Ostd.

O (‰ vs. VSMOW) (‰ vs. O -14 16 Ostd. 18 δ -16 Because of their differential masses, different stable iso- topes of a given element can be fractionated by natural processes. Knowledge of these fractionations can help in delineating the fate -18 of stable isotopes in the environment. One type of fractionation

is known as the equilibrium isotope effect: because molecules of -20 greater relative mass have greater dissociation energies, there is a preference for the heavy isotope to occur in one phase. The kinetic Low wine isotope effect is a result of unidirectional processes such as water High wine 18 Final product evaporating from a puddle. Evaporation causes O enrichment waterSource 16 in surface waters (Mook, 2006) as O preferentially partitions to Figure 3. δ18O values for water and samples throughout the the vapor phase. Progressive depletion of water vapor in 18O as air bourbon-making process at the Wild Turkey, Four Roses, and masses move from the equator toward the poles is an example of Jim Beam distilleries. fl d027-02 1st pgs page 25

Bourbon and springs in the Inner Bluegrass region of Kentucky 25

Department of Earth and Environmental Sciences, University of Stop A (Mile 2.5): Royal Spring, Georgetown, Kentucky Kentucky, personal communication, 2011). This supports our hypothesis that lighter isotope fractions are removed from the Royal Spring (Fig. 6) is the primary water supply for the mixture as water and ethanol evaporate in the stills. The evapora- city of Georgetown (population ~21,000), as well as portions of tion of lighter fractions is also responsible for the heavier δ18O Sadieville, Stamping Ground, Midway, and Lexington. In 1789, values of fi nal products. As each distiller’s product ages and Elijah Craig operated a distillery at Royal Spring (Allen, 1998), water is lost through the barrel, the bourbon left in the barrel which was designated the birthplace of bourbon by Richard becomes increasingly enriched in 18O (Fig. 4). Differences in 18O Collins in his 1874 . However, subsequent compositions among distilleries at each stage of the process may authors identifi ed evidence of whiskey-making elsewhere in refl ect the isotopic composition of the grains used (which were Kentucky between 1776 and 1781 (Regan and Regan, 2007; not examined in this study), temperatures of distillation, and/ Crowgey, 2008). Royal Spring emerges from the Grier Member or infl uences of the particular yeast strains involved. This may of the Lexington Limestone and sustains a tributary to North Elk- indicate a particular isotope signature for each distillery, which horn Creek. A karst conduit system carries all base fl ow and a could be of future use for quality control. However, further stud- large but unmeasured percentage of high fl ow discharge from the ies would be needed to evaluate this inference. Cane Run watershed to Royal Spring, which is located outside the boundary of the Cane Run watershed. FIELD STOPS (Fig. 5) Cane Run is a fourth-order stream that originates in central (Note: 1.0 mile = 1.6 km) Fayette County and fl ows north into North Elkhorn Creek in Scott County. The main stem of Cane Run is ~17 mi (27 km) Mileage Directions long and drains an area of 45 mi2 (116 km2). The watershed con- 0.0 Take I 75 S exit 126 for U.S. 62 toward sists of 25% urban land, primarily in northeast Lexington, and Georgetown/Cynthiana, Kentucky. 75% rural land, including farms, light industry, a quarry, and 0.4 Slight right onto U.S. 62 W/Cherry Blossom Way. rural and suburban residences. Discharge from the headwater 1.1 Turn right onto Paris Rd./Paris Pike (U.S. 460 W), tributaries of Cane Run is sustained in the dry season by urban continuing to follow Paris Rd. runoff and interbasinal, perched springs. However, the middle 1.7 Continue onto E. Main St. (U.S. 460 W). reach of Cane Run is normally dry and only carries discharge 2.3 Turn left onto S. Broadway St. (U.S. 25 S) during fl oods. Heavy rainfall causes sudden, large increases 2.4 Take 2nd right onto W. College St. of stream fl ow, followed by a brief recession and then a sud- den cessation of discharge. Swallets along the channel of Cane Run govern the partitioning of runoff between surface fl ow and -4 groundwater. When intense rainfall occurs in the dry season, recharge to the conduit is limited by the hydraulic capacity of -6 the conduit because such events may not fi ll it to full pipe fl ow. During the wet season, conduit discharge capacity is close to -8 maximum and surface fl ow extends further downstream, as conceptualized in Figure 7. -10 Qualitative and quantitative dye traces have been conducted within the Royal Spring basin in order to delineate the basin -12 boundaries (Fig. 8) and determine groundwater travel times. Groundwater velocities ranged from over 1 mi/h (1.6 km/h) dur- -14 ing storm events to less than 0.15 mi/h (0.24 km/h) in dry condi- O (‰ vs. (‰ O VSMOW) vs.

18 tions (Paylor and Currens, 2004). Contaminants may travel more δ -16 slowly, depending upon their sources and whether attenuation occurs in epikarst or within the conduit (e.g., as a consequence -18 of adsorption onto sediment [Reed et al., 2010]). Using two- dimensional, three-dimensional, and time-lapse electrical resis-

-20 tivity surveys (with salt injection), Zhu et al. (2011) suggested the location of the main conduit of the Royal Spring groundwater basin beneath the middle reach of Cane Run. Final 1 year Final 6 year Final 7 year Final 8 year Final 16 year Final 19 year Final 10 year Final 14 year Mileage Directions

Final rye whiskey 2.6 Head east on W. College St.; turn right onto S. Figure 4. δ18O values for fi nal products of the Wild Turkey, Four Broadway St. (U.S. 25 S); continue as U.S. 25 S Roses, and Jim Beam distilleries. becomes Lexington Rd./Georgetown Rd. fl d027-02 1st pgs page 26

26 Barton et al.

Figure 5. Field-trip route map through Inner Bluegrass region (from Google Maps, November 2011).

Figure 7. Conceptual diagram of fl ow along Cane Run (not to scale) Figure 6. Royal Spring (photo by A.E. Fryar, April 2009). (modifi ed from unpublished fi gure, Kentucky Geological Survey). fl d027-02 1st pgs page 27

Bourbon and springs in the Inner Bluegrass region of Kentucky 27

Figure 8. Inset of mapped karst groundwater basins in Fayette and Scott Counties, Kentucky (from Currens et al., 2002). fl d027-02 1st pgs page 28

28 Barton et al.

13.7 Bear right as U.S. 25 S merges with Newtown Pike settlement after it. The actual town was not formed until 1779. (KY 922 S). Various land uses have occurred around the springs during the 14.2 Continue onto Oliver Lewis Way (KY 922 S). past two centuries, including a gunpowder mill, stock farming, 14.4 Turn right onto KY 1681 W (Manchester St./Old commercial bourbon production, and dairying (O’Malley, ca. Frankfort Pike). 2006). Remnants of dry-stone fences are evidence of Irish and 15.6 Turn left onto McConnell Springs Rd. and left onto Scottish immigrant masons who began working in the 1830s. Cahill Dr.; take the 1st right onto Rebmann Ln. The city park was created in the 1990s after a failed effort to develop the site as an industrial park. Adjoining land use remains Stop B (Mile 15.9): McConnell Springs, partly industrial; in particular, Vulcan Materials quarries lime- Lexington, Kentucky stone from the Tyrone, Oregon, and Camp Nelson Formations more than 435 ft (133 m) beneath the springs. However, because The McConnell Springs site is located in a 26-acre (11-ha) of the presence of bentonite near the top of the Tyrone Forma- city park within the Wolf Run watershed in Lexington. The tion, the permeability of those units is so low that spring fl ow springs occur within a karst window, a cave passage unroofed by is not noticeably affected (Currens and Paylor, 2009; Friends of solution collapse. The Grier, Brannon, and Tanglewood Mem- McConnell Springs, 2010). bers of the Lexington Limestone are exposed on the site. The Blue Hole is the fi rst of two major springs seen in McCo- Grier Member, which is relatively transmissive because of disso- nnell Springs Park (Figs. 9, 10). The name of this artesian lution along fractures and bedding planes, underlies ~80% of the spring is derived from its color, which results from the depth site. The park contains more than 130 species of plants, includ- of the orifi ce (>15 ft [4.6 m]). Water discharging at Blue Hole ing bur oaks (Quercus macrocarpa) that are thought to remain has been traced from swallets and sinkholes as far as 2.5 mi from pre-settlement grassland savannas more than 250 years ago (4.0 km) south and southwest of the spring (Currens et al., (Friends of McConnell Springs, 2010). 2002; Friends of McConnell Springs, 2010) (Fig. 8). Discharge During the summer of 1775, a party from southwestern at Blue Hole is sensitive to rainfall. Water fl ows over the sur- Pennsylvania, including William McConnell, surveyed land face for tens of feet before sinking; it resurges at the second along the tributaries of Elkhorn Creek with the intent of fi ling artesian spring in the park, known as the Boils (Figs. 9, 11). At land claims with the state of , of which Kentucky was a this location, water is under suffi cient pressure (rising as much part. William McConnell claimed the “sinking springs” that now as 2 ft [0.6 m] above the spring pool after heavy rains) that it bear his name (O’Malley, ca. 2006). Legend has it that these pio- appears to be boiling, even though its temperature is ~56 °F neers were camped at the springs when they received word of (13 °C). Discharge from the Boils fl ows in a stream chan- the Battle of Lexington (Massachusetts) and decided to name the nel ~1000 ft (300 m) to the Final Sink, where it disappears

Figure 9. Conceptual block diagram of fl ow at McConnell Springs (not to scale) (modifi ed by S.F. Greb from Friends of McConnell Springs [2010]). fl d027-02 1st pgs page 29

Bourbon and springs in the Inner Bluegrass region of Kentucky 29

Stop C (Mile 35.2): Woodford Reserve Distillery, Versailles, Kentucky

Woodford Reserve Distillery (Fig. 12) traces its origins to 1797, when Elijah Pepper began making whiskey in Woodford County (Kentucky Distillers’ Association, 2010). Distilling on the current 72-acre (29-ha) site began ca. 1812 using water from Grassy Springs Branch of Glenns Creek (, 2008; Kentucky Historical Society, 2011). Elijah’s son Oscar Pepper employed James Crow as master distiller in the 1830s (National Park Service, 2008; Kentucky Historical Society, 2011). Leopold Labrot and James Graham purchased the distillery from the Pepper family in 1878 (, 2006). The Labrot & Graham Distillery operated until 1941 (Bourbon Central, 2011); Brown-Forman purchased it and reopened it in 1996 (Brown-Format, 2004). As a small-batch distiller, Wood- Figure 10. Blue Hole, McConnell Springs (photo by A.E. Fryar, ford Reserve uses a single, proprietary yeast strain to produce a April 2009). consistent fl avor profi le. The mash bill (recipe) consists of 72% corn, 18% rye (to which the spicy character of the bourbon is attributed), and 10% malted barley (Woodford Reserve, 2011). Woodford Reserve uses cypress fermentation tanks and triple underground and travels ~0.3 mi (0.5 km) to Preston’s Cave. distills its whiskey in three copper-pot stills (Fig. 13), depicted in Discharge from Preston’s Cave fl ows to Wolf Run and thence to the emblem stamped on the ends of its oak barrels. of Elkhorn Creek. Mileage Directions Mileage Directions 35.2 Continue on McCracken Pike/Glenns Creek Rd./ 16.1 Turn left from Rebmann Ln. onto Cahill Dr., right Martin Luther King Dr. (KY 1659 N). onto McConnell Springs Rd., then left onto Old 43.9 Turn left onto E. Main St. (U.S. 60 W). Frankfort Pike (KY 1681 W). 44.7 Turn right onto High St. (KY 420). 30.6 Turn left onto Steele Rd. (KY 1685). 44.9 Bear right onto Holmes St. (KY 2261). 33.6 Slight right onto KY 2331/McCracken-Steele Rd./ 46.6 Continue onto Owenton Rd. (U.S. 127 N). New Cut Rd. 46.8 Turn right onto Cove Spring Rd. and take the fi rst 34.4 Turn right onto McCracken Pike (KY 1659 N). left onto Deadhorse Rd. 35.2 Distillery is on the left (7855 McCracken Pike). 47.0 Travel to end of Deadhorse Rd.

Figure 11. The Boils, McConnell Springs (photo by A.E. Fryar, Figure 12. Woodford Reserve Distillery (photo by A.E. Fryar, Novem- April 2009). ber 2008). Warehouse for aging bourbon is at right. fl d027-02 1st pgs page 30

30 Barton et al.

Stop E (Mile 68.5): Four Roses Distillery, Lawrenceburg, Kentucky

In 1888, Paul Jones Jr. trademarked the name Four Roses as a brand of bourbon. The present distillery was built in 1910 in a Spanish mission style unusual for Kentucky. In 1922, the Paul Jones Company purchased the Frankfort Distilling Company, one of six distilleries authorized to produce bourbon for medici- nal purposes during Prohibition (Four Roses, 2011). Frankfort Distilling was sold to Seagram in 1943, which produced Four Roses straight bourbon whiskey (as opposed to blended whiskey) only for export for more than 40 years. In 2002, the distillery was acquired by the Kirin Brewery of Japan, which reintroduced Four Roses straight bourbon to the American market (Four Roses, 2011). Four Roses uses a combination of fi ve yeast strains and two mash bills to produce 10 bourbon recipes, each with its own fl avor profi le. Only one recipe is used in the Single Barrel prod- uct, whereas four recipes are combined to create Small Batch, and up to ten recipes are used to create Yellow Label. One mash bill includes 75% corn and 20% rye, whereas the other includes 60% corn and 35% rye; both include 5% malted barley (Four Roses, 2011). In contrast to Woodford Reserve, which ages its bourbon on-site, Four Roses uses warehouses in Cox’s Creek, Figure 13. Triple-pot stills at Woodford Reserve Distillery (photo by A.M. Barton, March 2009). Kentucky, approximately a 1 hour drive west of the distillery.

ACKNOWLEDGMENTS

Stop D (Mile 47.0): Cove Spring Park, Frankfort, Kentucky Chuck Taylor, Dorothy Vesper, Jim Currens, Brent Elliott, and Mike Sandy made helpful comments on the manuscript. Terry Cove Spring Park, which is owned by the City of Frank- Hounshell, Steve Greb, and Collie Rulo provided illustra- fort, consists of ~100 acres (40 ha) of meadows, wetlands, and tions. We appreciate the suggestion of the Cove Spring Park forested ravines within the Kentucky River valley. The park was stop by Marta Clepper and the guidance of Chris Romanek in established in part to preserve Braun’s rock-cress (Arabis per- isotopic analyses. Special thanks to Four Roses, Wild Turkey, stellata), an endangered wildfl ower (Frankfort Area Chamber and Jim Beam distilleries for their participation and help with of Commerce, 2011; U.S. Fish and Wildlife Service, 2011). In sample collection. 1800, settlers impounded Cove Spring to form Frankfort’s water supply, which was distributed through pipes made from cedar REFERENCES CITED logs cut on-site (Frankfort Area Chamber of Commerce, 2011). An overfl ow tower constructed of locally quarried limestone still Aley, T., 1984, Groundwater tracing in water pollution studies: National Spe- stands at the site. Clepper (2011) described the stratigraphy of leological Society Bulletin, v. 46, p. 17–20. Allen, F., 1998, The American spirit: American Heritage, v. 49, no. 3, p. 82–92. a 280.8-ft (85.6-m) measured section at the site, which extends Andrews, W.M., Jr., 2005, Geology and the Civil War in central Kentucky: from the Tyrone Formation along the valley fl oor to the upper Camp Nelson, in American Institute of Professional Geologists, 42nd tongue of the Tanglewood Member of the Lexington Limestone Annual Meeting, Field Trip Guidebook, 25 p. Bourbon Central, 2011, Woodford Reserve—review: http://www.bourbon- at the top of the escarpment (Table 1). central.com/bourbon-reviews/woodford-reserve-review/ (January 2012). Brown-Forman, 2004, Woodford Reserve tops 50,000 cases worldwide: http://www. Mileage Directions brown-forman.com/news/releases/release.aspx?rid=534 (January 2012). Carey, D.I., and Stickney, J.F., 2002, Groundwater resources of Anderson 47.3 From Cove Spring Rd., turn left onto Owenton County, Kentucky: Kentucky Geological Survey County Report 3, Series Rd. and immediately take the ramp onto U.S. 127 XII: http://www.uky.edu/KGS/water/library/gwatlas/Anderson/Anderson S/U.S. 421 N/Wilkinson Blvd. .htm (January 2012). Carey, D.I., and Stickney, J.F., 2004a, Groundwater resources of Scott County, Ken- 49.2 Turn right onto U.S. 127 S/W. Frankfort Connector; tucky: Kentucky Geological Survey County Report 105, Series XII: http:// continue on U.S. 127 S. www.uky.edu/KGS/water/library/gwatlas/Scott/Scott.htm (January 2012). 67.4 Turn right onto KY 513/Bonds Mill Rd./Hickory Carey, D.I., and Stickney, J.F., 2004b, Groundwater resources of Woodford County, Kentucky: Kentucky Geological Survey County Report 120, Series XII: Grove Rd. http://www.uky.edu/KGS/water/library/gwatlas/WOODFORD/Woodford 68.5 Turn right; destination will be on left. .htm (January 2012). fl d027-02 1st pgs page 31

Bourbon and springs in the Inner Bluegrass region of Kentucky 31

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