diff --git a/Project.toml b/Project.toml
index 7748ebc..e6c7eb7 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "Chron"
 uuid = "68885b1f-77b5-52a7-b2e7-6a8014c56b98"
 authors = ["C. Brenhin Keller <cbkeller@dartmouth.edu>"]
-version = "0.5.5"
+version = "0.6.0"
 
 [deps]
 DelimitedFiles = "8bb1440f-4735-579b-a4ab-409b98df4dab"
diff --git a/src/StratMetropolis.jl b/src/StratMetropolis.jl
index 38ee59c..18c3f99 100644
--- a/src/StratMetropolis.jl
+++ b/src/StratMetropolis.jl
@@ -438,17 +438,11 @@
         npoints = length(model_heights)
 
         # Calculate log likelihood of initial proposal
-        # Proposals younger than age constraint are given a pass if Age_Sidedness is -1 (maximum age)
-        # proposals older than age constraint are given a pass if Age_Sidedness is +1 (minimum age)
+
         sample_height = copy(Height)
         closest = findclosest(sample_height, model_heights)
         closest_model_ages = model_ages[closest]
-        @inbounds for i ∈ eachindex(ages,closest_model_ages)
-            if Age_Sidedness[i] == sign(closest_model_ages[i] - ages[i].μ)
-                closest_model_ages[i] = ages[i].μ
-            end
-        end
-        ll = strat_ll(closest_model_ages, ages)
+        ll = strat_ll(closest_model_ages, ages, Age_Sidedness)
         ll += normpdf_ll(Height, Height_sigma, sample_height)
 
         # Preallocate variables for MCMC proposals
@@ -473,14 +467,10 @@
 
             if rand() < 0.1
                 # Adjust heights
-                @inbounds for i ∈ eachindex(sample_heightₚ)
+                @inbounds for i ∈ eachindex(sample_heightₚ, closestₚ)
                     sample_heightₚ[i] += randn() * Height_sigma[i]
-                    closestₚ[i] = round(Int,(sample_heightₚ[i] - model_heights[1])/resolution)+1
-                    if closestₚ[i] < 1 # Check we're still within bounds
-                        closestₚ[i] = 1
-                    elseif closestₚ[i] > npoints
-                        closestₚ[i] = npoints
-                    end
+                    closestₚ[i] = round(Int,(sample_heightₚ[i] - first(model_heights))/resolution)+1
+                    closestₚ[i] = max(min(closestₚ[i], lastindex(model_agesₚ)), firstindex(model_agesₚ))
                 end
             else
                 # Adjust one point at a time then resolve conflicts
@@ -505,16 +495,11 @@
 
 
             # Calculate log likelihood of proposal
-            # Proposals younger than age constraint are given a pass if Age_Sidedness is -1 (maximum age)
-            # proposal older than age constraint are given a pass if Age_Sidedness is +1 (minimum age)
-            @inbounds for i ∈ eachindex(ages, closest_model_agesₚ)
+            adjust!(agesₚ, Chronometer, systematic)
+            @inbounds for i ∈ eachindex(closest_model_agesₚ, closestₚ)
                 closest_model_agesₚ[i] = model_agesₚ[closestₚ[i]]
-                if Age_Sidedness[i] == sign(closest_model_agesₚ[i] - ages[i].μ)
-                    closest_model_agesₚ[i] = ages[i].μ
-                end
             end
-            adjust!(agesₚ, Chronometer, systematic)
-            llₚ = strat_ll(closest_model_agesₚ, agesₚ)
+            llₚ = strat_ll(closest_model_agesₚ, agesₚ, Age_Sidedness)
             llₚ += normpdf_ll(Height, Height_sigma, sample_heightₚ)
 
             # Accept or reject proposal based on likelihood
@@ -549,14 +534,10 @@
 
             if rand() < 0.1
                 # Adjust heights
-                @inbounds for i ∈ eachindex(sample_heightₚ)
+                @inbounds for i ∈ eachindex(sample_heightₚ, closestₚ)
                     sample_heightₚ[i] += randn() * Height_sigma[i]
-                    closestₚ[i] = round(Int,(sample_heightₚ[i] - model_heights[1])/resolution)+1
-                    if closestₚ[i] < 1 # Check we're still within bounds
-                        closestₚ[i] = 1
-                    elseif closestₚ[i] > npoints
-                        closestₚ[i] = npoints
-                    end
+                    closestₚ[i] = round(Int,(sample_heightₚ[i] - first(model_heights))/resolution)+1
+                    closestₚ[i] = max(min(closestₚ[i], lastindex(model_agesₚ)), firstindex(model_agesₚ))
                 end
             else
                 # Adjust one point at a time then resolve conflicts
@@ -580,16 +561,11 @@
             end
 
             # Calculate log likelihood of proposal
-            # Proposals younger than age constraint are given a pass if Age_Sidedness is -1 (maximum age)
-            # proposal older than age constraint are given a pass if Age_Sidedness is +1 (minimum age)
-            @inbounds for i ∈ eachindex(ages, closest_model_agesₚ)
+            adjust!(agesₚ, Chronometer, systematic)
+            @inbounds for i ∈ eachindex(closest_model_agesₚ, closestₚ)
                 closest_model_agesₚ[i] = model_agesₚ[closestₚ[i]]
-                if Age_Sidedness[i] == sign(closest_model_agesₚ[i] - ages[i].μ)
-                    closest_model_agesₚ[i] = ages[i].μ
-                end
             end
-            adjust!(agesₚ, Chronometer, systematic)
-            llₚ = strat_ll(closest_model_agesₚ, agesₚ)
+            llₚ = strat_ll(closest_model_agesₚ, agesₚ, Age_Sidedness)
             llₚ += normpdf_ll(Height, Height_sigma, sample_heightₚ)
 
             # Accept or reject proposal based on likelihood
@@ -619,17 +595,10 @@
         npoints = length(model_heights)
 
         # Calculate log likelihood of initial proposal
-        # Proposals younger than age constraint are given a pass if Age_Sidedness is -1 (maximum age)
-        # proposals older than age constraint are given a pass if Age_Sidedness is +1 (minimum age)
         sample_height = copy(Height)
         closest = findclosest(sample_height, model_heights)
         closest_model_ages = model_ages[closest]
-        @inbounds for i ∈ eachindex(ages)
-            if Age_Sidedness[i] == sign(closest_model_ages[i] - ages[i].μ)
-                closest_model_ages[i] = ages[i].μ
-            end
-        end
-        ll = strat_ll(closest_model_ages, ages)
+        ll = strat_ll(closest_model_ages, ages, Age_Sidedness)
         ll += normpdf_ll(Height, Height_sigma, sample_height)
 
         # Ensure there is only one effective hiatus at most for each height node
@@ -673,14 +642,10 @@
 
             if rand() < 0.1
                 # Adjust heights
-                @inbounds for i ∈ eachindex(sample_heightₚ)
+                @inbounds for i ∈ eachindex(sample_heightₚ, closestₚ)
                     sample_heightₚ[i] += randn() * Height_sigma[i]
-                    closestₚ[i] = round(Int,(sample_heightₚ[i] - model_heights[1])/resolution)+1
-                    if closestₚ[i] < 1 # Check we're still within bounds
-                        closestₚ[i] = 1
-                    elseif closestₚ[i] > npoints
-                        closestₚ[i] = npoints
-                    end
+                    closestₚ[i] = round(Int,(sample_heightₚ[i] - first(model_heights))/resolution)+1
+                    closestₚ[i] = max(min(closestₚ[i], lastindex(model_agesₚ)), firstindex(model_agesₚ))
                 end
             else
                 # Adjust one point at a time then resolve conflicts
@@ -718,16 +683,11 @@
 
 
             # Calculate log likelihood of proposal
-            # Proposals younger than age constraint are given a pass if Age_Sidedness is -1 (maximum age)
-            # proposal older than age constraint are given a pass if Age_Sidedness is +1 (minimum age)
-            @inbounds for i ∈ eachindex(ages)
+            adjust!(agesₚ, Chronometer, systematic)
+            @inbounds for i ∈ eachindex(closest_model_agesₚ, closestₚ)
                 closest_model_agesₚ[i] = model_agesₚ[closestₚ[i]]
-                if Age_Sidedness[i] == sign(closest_model_agesₚ[i] - ages[i].μ)
-                    closest_model_agesₚ[i] = ages[i].μ
-                end
             end
-            adjust!(agesₚ, Chronometer, systematic)
-            llₚ = strat_ll(closest_model_agesₚ, agesₚ)
+            llₚ = strat_ll(closest_model_agesₚ, agesₚ, Age_Sidedness)
             llₚ += normpdf_ll(Height, Height_sigma, sample_heightₚ)
 
             # Add log likelihood for hiatus duration
@@ -767,14 +727,10 @@
 
             if rand() < 0.1
                 # Adjust heights
-                @inbounds for i ∈ eachindex(sample_heightₚ)
+                @inbounds for i ∈ eachindex(sample_heightₚ, closestₚ)
                     sample_heightₚ[i] += randn() * Height_sigma[i]
-                    closestₚ[i] = round(Int,(sample_heightₚ[i] - model_heights[1])/resolution)+1
-                    if closestₚ[i] < 1 # Check we're still within bounds
-                        closestₚ[i] = 1
-                    elseif closestₚ[i] > npoints
-                        closestₚ[i] = npoints
-                    end
+                    closestₚ[i] = round(Int,(sample_heightₚ[i] - first(model_heights))/resolution)+1
+                    closestₚ[i] = max(min(closestₚ[i], lastindex(model_agesₚ)), firstindex(model_agesₚ))
                 end
             else
                 # Adjust one point at a time then resolve conflicts
@@ -811,16 +767,11 @@
             end
 
             # Calculate log likelihood of proposal
-            # Proposals younger than age constraint are given a pass if Age_Sidedness is -1 (maximum age)
-            # proposal older than age constraint are given a pass if Age_Sidedness is +1 (minimum age)
-            @inbounds for i ∈ eachindex(ages)
+            adjust!(agesₚ, Chronometer, systematic)
+            @inbounds for i ∈ eachindex(closest_model_agesₚ, closestₚ)
                 closest_model_agesₚ[i] = model_agesₚ[closestₚ[i]]
-                if Age_Sidedness[i] == sign(closest_model_agesₚ[i] - ages[i].μ)
-                    closest_model_agesₚ[i] = ages[i].μ
-                end
             end
-            adjust!(agesₚ, Chronometer, systematic)
-            llₚ = strat_ll(closest_model_agesₚ, agesₚ)
+            llₚ = strat_ll(closest_model_agesₚ, agesₚ, Age_Sidedness)
             llₚ += normpdf_ll(Height, Height_sigma, sample_heightₚ)
 
             # Add log likelihood for hiatus duration
diff --git a/src/Utilities.jl b/src/Utilities.jl
index 5c4f77b..58ff13e 100644
--- a/src/Utilities.jl
+++ b/src/Utilities.jl
@@ -263,14 +263,44 @@
 ## --- log likelihood functions allowing for arbitrary Distributions
 
     # Use dispatch to let us reduce duplication
-    strat_ll(x, ages::AbstractVector{<:Normal}) = normpdf_ll(x, ages)
-    strat_ll(x::Real, age::Distribution) = logpdf(age, x)
     function strat_ll(x, ages)
         ll = zero(float(eltype(x)))
         @inbounds for i in eachindex(x, ages)
-            ll += logpdf(ages[i], x[i])
+            ll += fastlogpdf(ages[i], x[i])
         end
         return ll
     end
+    function strat_ll(x, ages, sidedness)
+        ll = zero(float(eltype(x)))
+        @inbounds for i in eachindex(x, ages, sidedness)
+            ll += if sidedness[i] > 0 # Minimum age
+                logcdf(ages[i], x[i])
+            elseif sidedness[i] < 0  # Maximum age
+                logccdf(ages[i], x[i])
+            else
+                fastlogpdf(ages[i], x[i])
+            end
+        end
+        return ll
+    end
+
+    # function strat_ll(x, ages, sidedness)
+    #     ll = zero(float(eltype(x)))
+    #     @inbounds for i in eachindex(x, ages, sidedness)
+    #         ll += if sidedness[i] == sign(x[i] - mean(ages[i]))
+    #             fastlogpdf(ages[i], mean(ages[i])))
+    #         else
+    #             fastlogpdf(ages[i], x[i]))
+    #         end
+    #     end
+    #     return ll
+    # end
+
+    fastlogpdf(d, x::Real) = logpdf(d, x)
+    function fastlogpdf(d::Normal, x::Real)
+        δ, σ = (x - d.μ), d.σ
+        - δ*δ/(2*σ*σ)
+    end
+
 
 ## --- End of File
diff --git a/test/testStratOnly.jl b/test/testStratOnly.jl
index 5c12929..aded5ba 100644
--- a/test/testStratOnly.jl
+++ b/test/testStratOnly.jl
@@ -28,9 +28,9 @@ config.sieve = round(Int,npoints_approx) # Record one out of every nsieve steps
 
 # Test that results match expectation, within some tolerance
 @test mdl.Age isa Vector{Float64}
-@test mdl.Age ≈ [775.639803231674, 764.7522135364757, 753.6908761271258, 743.7955507171365, 734.1450626270426, 724.4181380914805, 719.9344128500521, 715.730084005377, 711.5837749049695, 708.9681700152063, 706.4443998136725, 703.9187181054767, 701.2964403515165, 698.4067159228537, 694.0564170150618] atol=1
-@test mdl.Age_025CI ≈ [749.86998905391, 746.6946942599805, 744.0594596745302, 723.3563855942004, 718.369656399334, 715.5038496825758, 706.6306024739025, 703.0289240992544, 700.7652433271606, 697.635218301761, 695.8957733017851, 694.6899457591284, 693.7027382576433, 692.8123972703291, 681.3406483559285] atol=3
-@test mdl.Age_975CI ≈ [811.2671899519365, 797.4625865888173, 763.3573868897032, 760.0445173042854, 754.7002448815252, 733.5275337761803, 731.2848593336894, 728.2781265900221, 722.32529630248, 720.7715897667372, 718.9216447983222, 716.5564071732707, 713.0417479766365, 704.0850806207267, 702.9561071444978] atol=3
+@test mdl.Age ≈  [774.446455402488, 764.138871634567, 753.6234690338521, 743.7736679540459, 734.1288211670727, 724.4222568319159, 719.9641790169545, 715.7853469234702, 711.659901307201, 709.0927902799843, 706.6073112860937, 704.1349331543528, 701.576806557881, 698.7594637725156, 695.9077192905107] atol=1
+@test mdl.Age_025CI ≈ [749.7477463948217, 746.630273097855, 743.9690750302638, 723.4084389968576, 718.3588586689344, 715.5410003896017, 706.7023568283762, 703.1283100699234, 700.9213523438647, 697.904849247825, 696.2105445428034, 695.0433927602111, 694.1016935971145, 693.2625238063798, 684.8895558316834] atol=3
+@test mdl.Age_975CI ≈ [806.7021880750214, 794.9197023904139, 763.2743319392429, 760.0094083209071, 754.7169964175238, 733.5482560401001, 731.2806438300145, 728.3050781269916, 722.3491038457139, 720.830748668773, 718.9846443130959, 716.6641608791327, 713.2397206761551, 704.3594827974073, 703.4763901911105] atol=3
 # Test that all age-depth models are in stratigraphic order
 @test all([issorted(x, rev=true) for x in eachcol(agedist)])
 @test all(!isnan, agedist)
@@ -51,9 +51,9 @@ hiatus.Duration_sigma = [   3.1,    2.0 ]
 
 # Test that results match expectation, within some tolerance
 @test mdl.Age isa Vector{Float64}
-@test mdl.Age ≈ [776.1645401715448, 765.3913415310423, 754.4578701374423, 749.1402317775008, 729.1734073022601, 724.1504941010227, 720.8064612101196, 717.6325237531024, 714.3911204374407, 712.9981743647901, 701.8475241735739, 700.4609977090519, 699.1253113675604, 697.6951927842167, 693.5283072170754] atol=1
-@test mdl.Age_025CI ≈ [750.7546389575148, 747.721013702703, 745.2360260172313, 735.8600442968074, 717.8362687469073, 715.6571312160221, 709.9467580290137, 707.3352431871043, 705.6012864195188, 704.1631160813711, 693.9692554028434, 693.2871054139605, 692.6791996279173, 692.0920645898433, 681.1134640520288] atol=3
-@test mdl.Age_975CI ≈ [811.4534097071294, 797.7943496043165, 763.8616858646202, 761.1731148399618, 742.6187531312476, 732.7757692120042, 730.8844293232036, 728.3748870708009, 723.607690594645, 722.5139094919781, 711.2193585524507, 709.48421725086, 707.154594077965, 703.3249584517113, 702.2469721879497] atol=3
+@test mdl.Age ≈ [774.9621590393864, 764.7483478838244, 754.3928287806855, 749.1279876514806, 729.1819943547974, 724.1793043771663, 720.8913053718023, 717.7627759721249, 714.5509500060313, 713.2002472528285, 702.1296086101366, 700.7704707147774, 699.4643412956174, 698.0733121394825, 695.3696935693185] atol=1
+@test mdl.Age_025CI ≈ [750.6328462444853, 747.6305055671014, 745.2219453018333, 735.8795895625685, 717.8606462193696, 715.6849749469166, 710.1425439567424, 707.5591665793866, 705.808337538727, 704.4299789235162, 694.3410849948168, 693.699614909472, 693.1108571564564, 692.5485716537205, 684.6340487749085] atol=3
+@test mdl.Age_975CI ≈ [806.6715104282963, 794.8753648212958, 763.7844862197752, 761.1148678026058, 742.5015528417246, 732.771524797932, 730.9079222710706, 728.4137307378472, 723.6929471023955, 722.6480626953821, 711.3953411778708, 709.6936433474348, 707.3968615013218, 703.6205967015544, 702.7858695444451] atol=3
 # Test that all age-depth models are in stratigraphic order
 @test all([issorted(x, rev=true) for x in eachcol(agedist)])
 @test all(!isnan, agedist)
diff --git a/test/testUtilities.jl b/test/testUtilities.jl
index bc47498..6368376 100644
--- a/test/testUtilities.jl
+++ b/test/testUtilities.jl
@@ -50,12 +50,12 @@
 
 ## --- Other utility functions for log likelihoods
 
-    @test strat_ll(66.02, BilinearExponential(-5.9345103368858085, 66.00606672179812, 0.17739474265630253, 70.57882331291309, 0.6017142541555505)) ≈  (-3.251727600957773 -5.9345103368858085)
-    @test strat_ll(950, Radiocarbon(1000, 10, intcal13)) ≈ -7.342817323513984
+    @test strat_ll([66.02,], [BilinearExponential(-5.9345103368858085, 66.00606672179812, 0.17739474265630253, 70.57882331291309, 0.6017142541555505)]) ≈  (-3.251727600957773 -5.9345103368858085)
+    @test strat_ll([950,], [Radiocarbon(1000, 10, intcal13)]) ≈ -7.342817323513984
 
     @test strat_ll([0.0, 0.0], [Normal(0,1), Normal(0,1)]) ≈ 0
-    @test strat_ll([0.0, 0.5], [Normal(0,1), Uniform(0,1)]) ≈ -0.9189385332046728
-    @test strat_ll([0.0, 0.5, 66.02], [Normal(0,1), Uniform(0,1), BilinearExponential(-5.9345103368858085, 66.00606672179812, 0.17739474265630253, 70.57882331291309, 0.6017142541555505)]) ≈ (-0.9189385332046728 -3.251727600957773 -5.9345103368858085)
-    @test strat_ll([0.0, 0.5, 66.02, 900], [Normal(0,1), Uniform(0,1), BilinearExponential(-5.9345103368858085, 66.00606672179812, 0.17739474265630253, 70.57882331291309, 0.6017142541555505), Radiocarbon(1000, 10, intcal13)]) ≈ -26.680063245418374
+    @test strat_ll([0.0, 0.5], [Normal(0,1), Uniform(0,1)]) ≈ 0
+    @test strat_ll([0.0, 0.5, 66.02], [Normal(0,1), Uniform(0,1), BilinearExponential(-5.9345103368858085, 66.00606672179812, 0.17739474265630253, 70.57882331291309, 0.6017142541555505)]) ≈ (-3.251727600957773 -5.9345103368858085)
+    @test strat_ll([0.0, 0.5, 66.02, 900], [Normal(0,1), Uniform(0,1), BilinearExponential(-5.9345103368858085, 66.00606672179812, 0.17739474265630253, 70.57882331291309, 0.6017142541555505), Radiocarbon(1000, 10, intcal13)]) ≈ -25.761124712213704
 
 ## ---